Add --modules=node support

lib/runtime/dart/collection.js

Index: lib/runtime/dart/collection.js
diff --git a/lib/runtime/dart/collection.js b/lib/runtime/dart/collection.js
index 8937827d516b7b9a2801f4a17325d41b999457d3..c1fb5f1e2edaca093edf224dfd33549e6560f5f6 100644
--- a/lib/runtime/dart/collection.js
+++ b/lib/runtime/dart/collection.js
@@ -41,12 +41,12 @@ dart_library.library('dart/collection', null, /* Imports */[
     const _Equality = dart.typedef('_Equality', () => dart.functionType(core.bool, [K, K]));
     return _Equality;
   });
-  let _Equality = _Equality$();
+  const _Equality = _Equality$();
   const _Hasher$ = dart.generic(function(K) {
     const _Hasher = dart.typedef('_Hasher', () => dart.functionType(core.int, [K]));
     return _Hasher;
   });
-  let _Hasher = _Hasher$();
+  const _Hasher = _Hasher$();
   const HashMap$ = dart.generic(function(K, V) {
     class HashMap extends core.Object {
       static new(opts) {
@@ -112,7 +112,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return HashMap;
   });
-  let HashMap = HashMap$();
+  const HashMap = HashMap$();
   const SetMixin$ = dart.generic(function(E) {
     class SetMixin extends core.Object {
       [Symbol.iterator]() {
@@ -424,7 +424,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return SetMixin;
   });
-  let SetMixin = SetMixin$();
+  const SetMixin = SetMixin$();
   const SetBase$ = dart.generic(function(E) {
     class SetBase extends SetMixin$(E) {
       static setToString(set) {
@@ -437,7 +437,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return SetBase;
   });
-  let SetBase = SetBase$();
+  const SetBase = SetBase$();
   const _newSet = Symbol('_newSet');
   const _HashSetBase$ = dart.generic(function(E) {
     class _HashSetBase extends SetBase$(E) {
@@ -473,7 +473,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     dart.defineExtensionMembers(_HashSetBase, ['toSet']);
     return _HashSetBase;
   });
-  let _HashSetBase = _HashSetBase$();
+  const _HashSetBase = _HashSetBase$();
   const HashSet$ = dart.generic(function(E) {
     class HashSet extends core.Object {
       static new(opts) {
@@ -527,7 +527,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return HashSet;
   });
-  let HashSet = HashSet$();
+  const HashSet = HashSet$();
   const IterableMixin$ = dart.generic(function(E) {
     class IterableMixin extends core.Object {
       map(f) {
@@ -779,7 +779,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return IterableMixin;
   });
-  let IterableMixin = IterableMixin$();
+  const IterableMixin = IterableMixin$();
   const IterableBase$ = dart.generic(function(E) {
     class IterableBase extends core.Object {
       IterableBase() {
@@ -1164,7 +1164,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return IterableBase;
   });
-  let IterableBase = IterableBase$();
+  const IterableBase = IterableBase$();
   dart.defineLazyProperties(IterableBase, {
     get _toStringVisiting() {
       return [];
@@ -1207,7 +1207,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return HasNextIterator;
   });
-  let HasNextIterator = HasNextIterator$();
+  const HasNextIterator = HasNextIterator$();
   HasNextIterator._HAS_NEXT_AND_NEXT_IN_CURRENT = 0;
   HasNextIterator._NO_NEXT = 1;
   HasNextIterator._NOT_MOVED_YET = 2;
@@ -1284,7 +1284,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return LinkedHashMap;
   });
-  let LinkedHashMap = LinkedHashMap$();
+  const LinkedHashMap = LinkedHashMap$();
   const LinkedHashSet$ = dart.generic(function(E) {
     class LinkedHashSet extends core.Object {
       static new(opts) {
@@ -1339,7 +1339,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return LinkedHashSet;
   });
-  let LinkedHashSet = LinkedHashSet$();
+  const LinkedHashSet = LinkedHashSet$();
   const _modificationCount = Symbol('_modificationCount');
   const _length = Symbol('_length');
   const _next = Symbol('_next');
@@ -1477,7 +1477,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return LinkedList;
   });
-  let LinkedList = LinkedList$();
+  const LinkedList = LinkedList$();
   const _current = Symbol('_current');
   const _LinkedListIterator$ = dart.generic(function(E) {
     class _LinkedListIterator extends core.Object {
@@ -1510,7 +1510,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _LinkedListIterator;
   });
-  let _LinkedListIterator = _LinkedListIterator$();
+  const _LinkedListIterator = _LinkedListIterator$();
   class _LinkedListLink extends core.Object {
     _LinkedListLink() {
       this[_next] = null;
@@ -1558,7 +1558,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return LinkedListEntry;
   });
-  let LinkedListEntry = LinkedListEntry$();
+  const LinkedListEntry = LinkedListEntry$();
   const ListMixin$ = dart.generic(function(E) {
     class ListMixin extends core.Object {
       get iterator() {
@@ -2118,7 +2118,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return ListMixin;
   });
-  let ListMixin = ListMixin$();
+  const ListMixin = ListMixin$();
   const ListBase$ = dart.generic(function(E) {
     class ListBase extends dart.mixin(core.Object, ListMixin$(E)) {
       static listToString(list) {
@@ -2131,7 +2131,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return ListBase;
   });
-  let ListBase = ListBase$();
+  const ListBase = ListBase$();
   const __CastType0 = dart.typedef('__CastType0', () => dart.functionType(core.int, [dart.dynamic, dart.dynamic]));
   const MapMixin$ = dart.generic(function(K, V) {
     class MapMixin extends core.Object {
@@ -2192,12 +2192,12 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return MapMixin;
   });
-  let MapMixin = MapMixin$();
+  const MapMixin = MapMixin$();
   const MapBase$ = dart.generic(function(K, V) {
     class MapBase extends dart.mixin(core.Object, MapMixin$(K, V)) {}
     return MapBase;
   });
-  let MapBase = MapBase$();
+  const MapBase = MapBase$();
   const _UnmodifiableMapMixin$ = dart.generic(function(K, V) {
     class _UnmodifiableMapMixin extends core.Object {
       set(key, value) {
@@ -2234,7 +2234,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _UnmodifiableMapMixin;
   });
-  let _UnmodifiableMapMixin = _UnmodifiableMapMixin$();
+  const _UnmodifiableMapMixin = _UnmodifiableMapMixin$();
   const UnmodifiableMapBase$ = dart.generic(function(K, V) {
     class UnmodifiableMapBase extends dart.mixin(MapBase$(K, V), _UnmodifiableMapMixin$(K, V)) {
       UnmodifiableMapBase() {
@@ -2243,7 +2243,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     }
     return UnmodifiableMapBase;
   });
-  let UnmodifiableMapBase = UnmodifiableMapBase$();
+  const UnmodifiableMapBase = UnmodifiableMapBase$();
   const _map = Symbol('_map');
   const _MapBaseValueIterable$ = dart.generic(function(V) {
     class _MapBaseValueIterable extends IterableBase$(V) {
@@ -2288,7 +2288,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return _MapBaseValueIterable;
   });
-  let _MapBaseValueIterable = _MapBaseValueIterable$();
+  const _MapBaseValueIterable = _MapBaseValueIterable$();
   const _keys = Symbol('_keys');
   const _MapBaseValueIterator$ = dart.generic(function(V) {
     class _MapBaseValueIterator extends core.Object {
@@ -2316,7 +2316,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _MapBaseValueIterator;
   });
-  let _MapBaseValueIterator = _MapBaseValueIterator$();
+  const _MapBaseValueIterator = _MapBaseValueIterator$();
   const MapView$ = dart.generic(function(K, V) {
     class MapView extends core.Object {
       MapView(map) {
@@ -2392,7 +2392,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return MapView;
   });
-  let MapView = MapView$();
+  const MapView = MapView$();
   const UnmodifiableMapView$ = dart.generic(function(K, V) {
     class UnmodifiableMapView extends dart.mixin(MapView$(K, V), _UnmodifiableMapMixin$(K, V)) {
       UnmodifiableMapView() {
@@ -2401,7 +2401,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     }
     return UnmodifiableMapView;
   });
-  let UnmodifiableMapView = UnmodifiableMapView$();
+  const UnmodifiableMapView = UnmodifiableMapView$();
   class Maps extends core.Object {
     static containsValue(map, value) {
       for (let v of map.values) {
@@ -2538,7 +2538,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return Queue;
   });
-  let Queue = Queue$();
+  const Queue = Queue$();
   const _element = Symbol('_element');
   const _link = Symbol('_link');
   const _asNonSentinelEntry = Symbol('_asNonSentinelEntry');
@@ -2603,7 +2603,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return DoubleLinkedQueueEntry;
   });
-  let DoubleLinkedQueueEntry = DoubleLinkedQueueEntry$();
+  const DoubleLinkedQueueEntry = DoubleLinkedQueueEntry$();
   const _DoubleLinkedQueueEntrySentinel$ = dart.generic(function(E) {
     class _DoubleLinkedQueueEntrySentinel extends DoubleLinkedQueueEntry$(E) {
       _DoubleLinkedQueueEntrySentinel() {
@@ -2633,7 +2633,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _DoubleLinkedQueueEntrySentinel;
   });
-  let _DoubleLinkedQueueEntrySentinel = _DoubleLinkedQueueEntrySentinel$();
+  const _DoubleLinkedQueueEntrySentinel = _DoubleLinkedQueueEntrySentinel$();
   const _sentinel = Symbol('_sentinel');
   const _elementCount = Symbol('_elementCount');
   const _filter = Symbol('_filter');
@@ -2794,7 +2794,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return DoubleLinkedQueue;
   });
-  let DoubleLinkedQueue = DoubleLinkedQueue$();
+  const DoubleLinkedQueue = DoubleLinkedQueue$();
   const _nextEntry = Symbol('_nextEntry');
   const _DoubleLinkedQueueIterator$ = dart.generic(function(E) {
     class _DoubleLinkedQueueIterator extends core.Object {
@@ -2824,7 +2824,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _DoubleLinkedQueueIterator;
   });
-  let _DoubleLinkedQueueIterator = _DoubleLinkedQueueIterator$();
+  const _DoubleLinkedQueueIterator = _DoubleLinkedQueueIterator$();
   const _head = Symbol('_head');
   const _tail = Symbol('_tail');
   const _table = Symbol('_table');
@@ -3156,7 +3156,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return ListQueue;
   });
-  let ListQueue = ListQueue$();
+  const ListQueue = ListQueue$();
   ListQueue._INITIAL_CAPACITY = 8;
   const _queue = Symbol('_queue');
   const _end = Symbol('_end');
@@ -3191,12 +3191,12 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _ListQueueIterator;
   });
-  let _ListQueueIterator = _ListQueueIterator$();
+  const _ListQueueIterator = _ListQueueIterator$();
   const _Predicate$ = dart.generic(function(T) {
     const _Predicate = dart.typedef('_Predicate', () => dart.functionType(core.bool, [T]));
     return _Predicate;
   });
-  let _Predicate = _Predicate$();
+  const _Predicate = _Predicate$();
   const _SplayTreeNode$ = dart.generic(function(K) {
     class _SplayTreeNode extends core.Object {
       _SplayTreeNode(key) {
@@ -3210,7 +3210,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeNode;
   });
-  let _SplayTreeNode = _SplayTreeNode$();
+  const _SplayTreeNode = _SplayTreeNode$();
   const _SplayTreeMapNode$ = dart.generic(function(K, V) {
     class _SplayTreeMapNode extends _SplayTreeNode$(K) {
       _SplayTreeMapNode(key, value) {
@@ -3223,7 +3223,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeMapNode;
   });
-  let _SplayTreeMapNode = _SplayTreeMapNode$();
+  const _SplayTreeMapNode = _SplayTreeMapNode$();
   const _dummy = Symbol('_dummy');
   const _root = Symbol('_root');
   const _count = Symbol('_count');
@@ -3380,7 +3380,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTree;
   });
-  let _SplayTree = _SplayTree$();
+  const _SplayTree = _SplayTree$();
   const _comparator = Symbol('_comparator');
   const _validKey = Symbol('_validKey');
   const SplayTreeMap$ = dart.generic(function(K, V) {
@@ -3603,7 +3603,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return SplayTreeMap;
   });
-  let SplayTreeMap = SplayTreeMap$();
+  const SplayTreeMap = SplayTreeMap$();
   const _workList = Symbol('_workList');
   const _tree = Symbol('_tree');
   const _currentNode = Symbol('_currentNode');
@@ -3687,7 +3687,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeIterator;
   });
-  let _SplayTreeIterator = _SplayTreeIterator$();
+  const _SplayTreeIterator = _SplayTreeIterator$();
   const _copyNode = Symbol('_copyNode');
   const _SplayTreeKeyIterable$ = dart.generic(function(K) {
     class _SplayTreeKeyIterable extends IterableBase$(K) {
@@ -3720,7 +3720,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     dart.defineExtensionMembers(_SplayTreeKeyIterable, ['toSet', 'length', 'isEmpty', 'iterator']);
     return _SplayTreeKeyIterable;
   });
-  let _SplayTreeKeyIterable = _SplayTreeKeyIterable$();
+  const _SplayTreeKeyIterable = _SplayTreeKeyIterable$();
   const _SplayTreeValueIterable$ = dart.generic(function(K, V) {
     class _SplayTreeValueIterable extends IterableBase$(V) {
       _SplayTreeValueIterable(map) {
@@ -3744,7 +3744,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     dart.defineExtensionMembers(_SplayTreeValueIterable, ['length', 'isEmpty', 'iterator']);
     return _SplayTreeValueIterable;
   });
-  let _SplayTreeValueIterable = _SplayTreeValueIterable$();
+  const _SplayTreeValueIterable = _SplayTreeValueIterable$();
   const _SplayTreeKeyIterator$ = dart.generic(function(K) {
     class _SplayTreeKeyIterator extends _SplayTreeIterator$(K) {
       _SplayTreeKeyIterator(map) {
@@ -3760,7 +3760,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeKeyIterator;
   });
-  let _SplayTreeKeyIterator = _SplayTreeKeyIterator$();
+  const _SplayTreeKeyIterator = _SplayTreeKeyIterator$();
   const _SplayTreeValueIterator$ = dart.generic(function(K, V) {
     class _SplayTreeValueIterator extends _SplayTreeIterator$(V) {
       _SplayTreeValueIterator(map) {
@@ -3776,7 +3776,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeValueIterator;
   });
-  let _SplayTreeValueIterator = _SplayTreeValueIterator$();
+  const _SplayTreeValueIterator = _SplayTreeValueIterator$();
   const _SplayTreeNodeIterator$ = dart.generic(function(K) {
     class _SplayTreeNodeIterator extends _SplayTreeIterator$(_SplayTreeNode$(K)) {
       _SplayTreeNodeIterator(tree) {
@@ -3799,7 +3799,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _SplayTreeNodeIterator;
   });
-  let _SplayTreeNodeIterator = _SplayTreeNodeIterator$();
+  const _SplayTreeNodeIterator = _SplayTreeNodeIterator$();
   const _clone = Symbol('_clone');
   const SplayTreeSet$ = dart.generic(function(E) {
     class SplayTreeSet extends dart.mixin(_SplayTree$(E), IterableMixin$(E), SetMixin$(E)) {
@@ -3975,7 +3975,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return SplayTreeSet;
   });
-  let SplayTreeSet = SplayTreeSet$();
+  const SplayTreeSet = SplayTreeSet$();
   const _strings = Symbol('_strings');
   const _nums = Symbol('_nums');
   const _rest = Symbol('_rest');
@@ -4286,7 +4286,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _HashMap;
   });
-  let _HashMap = _HashMap$();
+  const _HashMap = _HashMap$();
   const _IdentityHashMap$ = dart.generic(function(K, V) {
     class _IdentityHashMap extends _HashMap$(K, V) {
       _IdentityHashMap() {
@@ -4306,7 +4306,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     }
     return _IdentityHashMap;
   });
-  let _IdentityHashMap = _IdentityHashMap$();
+  const _IdentityHashMap = _IdentityHashMap$();
   const _equals = Symbol('_equals');
   const _hashCode = Symbol('_hashCode');
   const _CustomHashMap$ = dart.generic(function(K, V) {
@@ -4360,7 +4360,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _CustomHashMap;
   });
-  let _CustomHashMap = _CustomHashMap$();
+  const _CustomHashMap = _CustomHashMap$();
   const HashMapKeyIterable$ = dart.generic(function(E) {
     class HashMapKeyIterable extends IterableBase$(E) {
       HashMapKeyIterable(map) {
@@ -4404,7 +4404,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return HashMapKeyIterable;
   });
-  let HashMapKeyIterable = HashMapKeyIterable$();
+  const HashMapKeyIterable = HashMapKeyIterable$();
   const _offset = Symbol('_offset');
   const HashMapKeyIterator$ = dart.generic(function(E) {
     class HashMapKeyIterator extends core.Object {
@@ -4439,7 +4439,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return HashMapKeyIterator;
   });
-  let HashMapKeyIterator = HashMapKeyIterator$();
+  const HashMapKeyIterator = HashMapKeyIterator$();
   const _modifications = Symbol('_modifications');
   const _value = Symbol('_value');
   const _newLinkedCell = Symbol('_newLinkedCell');
@@ -4746,7 +4746,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _LinkedHashMap;
   });
-  let _LinkedHashMap = _LinkedHashMap$();
+  const _LinkedHashMap = _LinkedHashMap$();
   const _LinkedIdentityHashMap$ = dart.generic(function(K, V) {
     class _LinkedIdentityHashMap extends _LinkedHashMap$(K, V) {
       _LinkedIdentityHashMap() {
@@ -4767,7 +4767,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     }
     return _LinkedIdentityHashMap;
   });
-  let _LinkedIdentityHashMap = _LinkedIdentityHashMap$();
+  const _LinkedIdentityHashMap = _LinkedIdentityHashMap$();
   const _LinkedCustomHashMap$ = dart.generic(function(K, V) {
     class _LinkedCustomHashMap extends _LinkedHashMap$(K, V) {
       _LinkedCustomHashMap(equals, hashCode, validKey) {
@@ -4817,7 +4817,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _LinkedCustomHashMap;
   });
-  let _LinkedCustomHashMap = _LinkedCustomHashMap$();
+  const _LinkedCustomHashMap = _LinkedCustomHashMap$();
   class LinkedHashMapCell extends core.Object {
     LinkedHashMapCell(key, value) {
       this[_key] = key;
@@ -4874,7 +4874,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return LinkedHashMapKeyIterable;
   });
-  let LinkedHashMapKeyIterable = LinkedHashMapKeyIterable$();
+  const LinkedHashMapKeyIterable = LinkedHashMapKeyIterable$();
   const _cell = Symbol('_cell');
   const LinkedHashMapKeyIterator$ = dart.generic(function(E) {
     class LinkedHashMapKeyIterator extends core.Object {
@@ -4908,7 +4908,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return LinkedHashMapKeyIterator;
   });
-  let LinkedHashMapKeyIterator = LinkedHashMapKeyIterator$();
+  const LinkedHashMapKeyIterator = LinkedHashMapKeyIterator$();
   const _elements = Symbol('_elements');
   const _computeElements = Symbol('_computeElements');
   const _contains = Symbol('_contains');
@@ -5170,7 +5170,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return _HashSet;
   });
-  let _HashSet = _HashSet$();
+  const _HashSet = _HashSet$();
   const _IdentityHashSet$ = dart.generic(function(E) {
     class _IdentityHashSet extends _HashSet$(E) {
       _IdentityHashSet() {
@@ -5196,7 +5196,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _IdentityHashSet;
   });
-  let _IdentityHashSet = _IdentityHashSet$();
+  const _IdentityHashSet = _IdentityHashSet$();
   const _equality = Symbol('_equality');
   const _hasher = Symbol('_hasher');
   const _CustomHashSet$ = dart.generic(function(E) {
@@ -5249,7 +5249,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     dart.defineExtensionMembers(_CustomHashSet, ['contains']);
     return _CustomHashSet;
   });
-  let _CustomHashSet = _CustomHashSet$();
+  const _CustomHashSet = _CustomHashSet$();
   const HashSetIterator$ = dart.generic(function(E) {
     class HashSetIterator extends core.Object {
       HashSetIterator(set, elements) {
@@ -5283,7 +5283,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return HashSetIterator;
   });
-  let HashSetIterator = HashSetIterator$();
+  const HashSetIterator = HashSetIterator$();
   const _unsupported = Symbol('_unsupported');
   const _LinkedHashSet$ = dart.generic(function(E) {
     class _LinkedHashSet extends _HashSetBase$(E) {
@@ -5589,7 +5589,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     ]);
     return _LinkedHashSet;
   });
-  let _LinkedHashSet = _LinkedHashSet$();
+  const _LinkedHashSet = _LinkedHashSet$();
   const _LinkedIdentityHashSet$ = dart.generic(function(E) {
     class _LinkedIdentityHashSet extends _LinkedHashSet$(E) {
       _LinkedIdentityHashSet() {
@@ -5616,7 +5616,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return _LinkedIdentityHashSet;
   });
-  let _LinkedIdentityHashSet = _LinkedIdentityHashSet$();
+  const _LinkedIdentityHashSet = _LinkedIdentityHashSet$();
   const _LinkedCustomHashSet$ = dart.generic(function(E) {
     class _LinkedCustomHashSet extends _LinkedHashSet$(E) {
       _LinkedCustomHashSet(equality, hasher, validKey) {
@@ -5681,7 +5681,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     dart.defineExtensionMembers(_LinkedCustomHashSet, ['contains']);
     return _LinkedCustomHashSet;
   });
-  let _LinkedCustomHashSet = _LinkedCustomHashSet$();
+  const _LinkedCustomHashSet = _LinkedCustomHashSet$();
   class LinkedHashSetCell extends core.Object {
     LinkedHashSetCell(element) {
       this[_element] = element;
@@ -5724,7 +5724,7 @@ dart_library.library('dart/collection', null, /* Imports */[
     });
     return LinkedHashSetIterator;
   });
-  let LinkedHashSetIterator = LinkedHashSetIterator$();
+  const LinkedHashSetIterator = LinkedHashSetIterator$();
   // Exports:
   exports.UnmodifiableListView$ = UnmodifiableListView$;
   exports.HashMap$ = HashMap$;