fixes #177, FunctionDeclarationStatement and closing over `this`

lib/runtime/dart/collection.js

 var collection = dart.defineLibrary(collection, {});
 var _internal = dart.lazyImport(_internal);
 var core = dart.import(core);
 var _js_helper = dart.lazyImport(_js_helper);
 var math = dart.lazyImport(math);
 (function(exports, _internal, core, _js_helper, math) {
   'use strict';
   let _source = Symbol('_source');
   let UnmodifiableListView$ = dart.generic(function(E) {
     class UnmodifiableListView extends _internal.UnmodifiableListBase$(E) {
@@ skipping 3067 matching lines @@
       clear() {
         this[_clear]();
       }
       containsKey(key) {
         return dart.notNull(this[_validKey](key)) && this[_splay](dart.as(key, K)) == 0;
       }
       containsValue(value) {
         let found = false;
         let initialSplayCount = this[_splayCount];
         // Function visit: (_SplayTreeMapNode<dynamic, dynamic>) → bool
-        function visit(node) {
+        let visit = (node => {
           while (node != null) {
             if (dart.equals(node.value, value))
               return true;
             if (initialSplayCount != this[_splayCount]) {
               throw new core.ConcurrentModificationError(this);
             }
             if (dart.notNull(node.right != null) && dart.notNull(visit(dart.as(node.right, _SplayTreeMapNode))))
               return true;
             node = dart.as(node.left, _SplayTreeMapNode);
           }
           return false;
-        }
+        }).bind(this);
         return visit(dart.as(this[_root], _SplayTreeMapNode));
       }
       get keys() {
         return new (_SplayTreeKeyIterable$(K))(this);
       }
       get values() {
         return new (_SplayTreeValueIterable$(K, V))(this);
       }
       toString() {
         return Maps.mapToString(this);
@@ skipping 2040 matching lines @@
   exports.LinkedHashMapKeyIterable$ = LinkedHashMapKeyIterable$;
   exports.LinkedHashMapKeyIterable = LinkedHashMapKeyIterable;
   exports.LinkedHashMapKeyIterator$ = LinkedHashMapKeyIterator$;
   exports.LinkedHashMapKeyIterator = LinkedHashMapKeyIterator;
   exports.HashSetIterator$ = HashSetIterator$;
   exports.HashSetIterator = HashSetIterator;
   exports.LinkedHashSetCell = LinkedHashSetCell;
   exports.LinkedHashSetIterator$ = LinkedHashSetIterator$;
   exports.LinkedHashSetIterator = LinkedHashSetIterator;
 })(collection, _internal, core, _js_helper, math);