Reapply "New implementation of {,Linked}Hash{Set,Map}."

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
index e60f8c9913b75e69a458ea4873fdff7f301423d5..9f8155d8d2a3a940e941438f935568c09dd9f1c2 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
@@ -306,7 +306,7 @@ class FieldTypesRegistry {
     // TODO(sgjesse): Handle field types for classes with more than one
     // constructor.
     if (ctors.length == 2) {
-      optimizedFunctions.forEach((Element field, _) {
+      optimizedFunctions.keys.toList().forEach((Element field) {
         if (identical(field.enclosingElement, cls)) {
           scheduleRecompilation(field);
         }
@@ -347,12 +347,12 @@ class FieldTypesRegistry {
     // TODO(sgjesse): Take the type of the setter into account.
     if (setterSelectorsUsed.contains(setter.name)) return;
     setterSelectorsUsed.add(setter.name);
-    optimizedStaticFunctions.forEach((Element field, _) {
+    optimizedStaticFunctions.keys.toList().forEach((Element field) {
       if (field.name == setter.name) {
         scheduleRecompilation(field);
       }
     });
-    optimizedFunctions.forEach((Element field, _) {
+    optimizedFunctions.keys.toList().forEach((Element field) {
       if (field.name == setter.name) {
         scheduleRecompilation(field);
       }
@@ -622,14 +622,14 @@ class JavaScriptBackend extends Backend {
   CodeEmitterTask emitter;
 
   /**
-   * The generated code as a js AST for compiled methods. 
+   * The generated code as a js AST for compiled methods.
    */
   Map<Element, js.Expression> get generatedCode {
     return compiler.enqueuer.codegen.generatedCode;
   }
 
   /**
-   * The generated code as a js AST for compiled bailout methods. 
+   * The generated code as a js AST for compiled bailout methods.
    */
   final Map<Element, js.Expression> generatedBailoutCode =
       new Map<Element, js.Expression>();
@@ -908,7 +908,7 @@ class JavaScriptBackend extends Backend {
       // The backend will use a literal list to initialize the entries
       // of the map.
       if (enqueuer.isResolutionQueue) {
-        enqueuer.registerInstantiatedClass(compiler.listClass); 
+        enqueuer.registerInstantiatedClass(compiler.listClass);
         enqueuer.registerInstantiatedClass(compiler.mapLiteralClass);
       }
     }