Typecheck constructor initializers properly

test/codegen/expect/collection/collection.js

Index: test/codegen/expect/collection/collection.js
diff --git a/test/codegen/expect/collection/collection.js b/test/codegen/expect/collection/collection.js
index 7286f23665d9eef1cc464f14801fe6b38d0cc894..44859ab92f74235ccd85be6f057b88cdb644e236 100644
--- a/test/codegen/expect/collection/collection.js
+++ b/test/codegen/expect/collection/collection.js
@@ -287,7 +287,7 @@ var collection;
       _CustomHashMap(_equals, _hashCode, validKey) {
         this._equals = _equals;
         this._hashCode = _hashCode;
-        this._validKey = validKey !== null ? validKey : (v) => dart.is(v, K);
+        this._validKey = dart.as(validKey !== null ? validKey : (v) => dart.is(v, K), _Predicate);
         super._HashMap();
       }
       get(key) {
@@ -680,7 +680,7 @@ var collection;
       _LinkedCustomHashMap(_equals, _hashCode, validKey) {
         this._equals = _equals;
         this._hashCode = _hashCode;
-        this._validKey = validKey !== null ? validKey : (v) => dart.is(v, K);
+        this._validKey = dart.as(validKey !== null ? validKey : (v) => dart.is(v, K), _Predicate);
         super._LinkedHashMap();
       }
       get(key) {
@@ -1045,7 +1045,7 @@ var collection;
       _CustomHashSet(_equality, _hasher, validKey) {
         this._equality = _equality;
         this._hasher = _hasher;
-        this._validKey = validKey !== null ? validKey : (x) => dart.is(x, E);
+        this._validKey = dart.as(validKey !== null ? validKey : (x) => dart.is(x, E), _Predicate);
         super._HashSet();
       }
       _newSet() {
@@ -1413,7 +1413,7 @@ var collection;
       _LinkedCustomHashSet(_equality, _hasher, validKey) {
         this._equality = _equality;
         this._hasher = _hasher;
-        this._validKey = validKey !== null ? validKey : (x) => dart.is(x, E);
+        this._validKey = dart.as(validKey !== null ? validKey : (x) => dart.is(x, E), _Predicate);
         super._LinkedHashSet();
       }
       _newSet() {
@@ -4216,8 +4216,8 @@ var collection;
           compare = null;
         if (isValidKey === void 0)
           isValidKey = null;
-        this._comparator = compare === null ? core.Comparable.compare : compare;
-        this._validKey = isValidKey !== null ? isValidKey : (v) => dart.is(v, K);
+        this._comparator = dart.as(compare === null ? core.Comparable.compare : compare, core.Comparator);
+        this._validKey = dart.as(isValidKey !== null ? isValidKey : (v) => dart.is(v, K), _Predicate);
         super._SplayTree();
       }
       SplayTreeMap$from(other, compare, isValidKey) {
@@ -4576,8 +4576,8 @@ var collection;
           compare = null;
         if (isValidKey === void 0)
           isValidKey = null;
-        this._comparator = compare === null ? core.Comparable.compare : compare;
-        this._validKey = isValidKey !== null ? isValidKey : (v) => dart.is(v, E);
+        this._comparator = dart.as(compare === null ? core.Comparable.compare : compare, core.Comparator);
+        this._validKey = dart.as(isValidKey !== null ? isValidKey : (v) => dart.is(v, E), _Predicate);
         super._SplayTree();
       }
       SplayTreeSet$from(elements, compare, isValidKey) {