dart2js: Destroy some type inference graph edges after type inference.

pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library type_graph_inferrer;
 
 import 'dart:collection' show Queue;
 
 import '../common.dart';
 import '../common/names.dart' show
@@ skipping 1269 matching lines @@
 
     List<Element> result = <Element>[];
     for (int i = 0; i <= max; i++) {
       Setlet<Element> set = methodSizes[i];
       if (set != null) result.addAll(set);
     }
     return result;
   }
 
   void clear() {
+    void cleanup(TypeInformation info) => info.cleanup();
+
+    allocatedCalls.forEach(cleanup);
     allocatedCalls.clear();
+
     defaultTypeOfParameter.clear();
-    types.typeInformations.values.forEach((info) => info.clear());
+
+    types.typeInformations.values.forEach(cleanup);
+
+    types.allocatedTypes.forEach(cleanup);
     types.allocatedTypes.clear();
+
     types.concreteTypes.clear();
+
+    types.allocatedClosures.forEach(cleanup);
     types.allocatedClosures.clear();
+
     analyzedElements.clear();
     generativeConstructorsExposingThis.clear();
+   
+    types.allocatedMaps.values.forEach(cleanup);
+    types.allocatedLists.values.forEach(cleanup);
   }
 
   Iterable<Element> getCallersOf(Element element) {
     if (compiler.disableTypeInference) {
       throw new UnsupportedError(
           "Cannot query the type inferrer when type inference is disabled.");
     }
     MemberTypeInformation info = types.getInferredTypeOf(element);
     return info.callers;
   }
@@ skipping 115 matching lines @@
   bool isCalledOnce(Element element) {
     if (compiler.disableTypeInference) return false;
     MemberTypeInformation info = inferrer.types.getInferredTypeOf(element);
     return info.isCalledOnce();
   }
 
   void clear() {
     inferrer.clear();
   }
 }