Support new malformed types semantics.

sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart

Index: sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart
diff --git a/sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart b/sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart
index 317e0b6f4bfaf43c482adb9c356fc47c1a644d5a..25812f1e53441a1a2374fc49ebe52df41a27ee42 100644
--- a/sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart
+++ b/sdk/lib/_internal/compiler/implementation/types/simple_types_inferrer.dart
@@ -751,7 +751,7 @@ class InternalSimpleTypesInferrer extends TypesInferrer {
         mappedType = nullType;
       } else if (type.isVoid) {
         mappedType = nullType;
-      } else if (type.isDynamic) {
+      } else if (type.treatAsDynamic) {
         return dynamicType;
       } else if (!compiler.world.hasAnySubtype(type.element)) {
         mappedType = new TypeMask.nonNullExact(rawTypeOf(type.element));
@@ -786,7 +786,7 @@ class InternalSimpleTypesInferrer extends TypesInferrer {
     if (isNativeElement(element) && element.isField()) {
       if (type == null) {
         InterfaceType rawType = element.computeType(compiler).asRaw();
-        info.type = type = rawType.isDynamic
+        info.type = type = rawType.treatAsDynamic
             ? dynamicType
             : new TypeMask.subtype(rawType);
       }