Implement subtype checks on type arguments.

sdk/lib/_internal/compiler/implementation/universe/universe.dart

Index: sdk/lib/_internal/compiler/implementation/universe/universe.dart
diff --git a/sdk/lib/_internal/compiler/implementation/universe/universe.dart b/sdk/lib/_internal/compiler/implementation/universe/universe.dart
index 446d835cea79aa625319fcdbd7aa11d9f7ac9edc..5675d8b420a77adc01b998e284306c30d0f7dc9f 100644
--- a/sdk/lib/_internal/compiler/implementation/universe/universe.dart
+++ b/sdk/lib/_internal/compiler/implementation/universe/universe.dart
@@ -35,6 +35,7 @@ class Universe {
    * Invariant: Elements are declaration elements.
    */
   final Set<ClassElement> instantiatedClasses;
+  final Set<DartType> instantiatedTypes;

[ngeoffray, 2012/12/13 13:34:58]

TODO: merge these sets?

[karlklose, 2012/12/13 14:37:34]

Done.

 
   /**
    * Documentation wanted -- johnniwinther
@@ -52,6 +53,7 @@ class Universe {
   Universe() : generatedCode = new Map<Element, CodeBuffer>(),
                generatedBailoutCode = new Map<Element, CodeBuffer>(),
                instantiatedClasses = new Set<ClassElement>(),
+               instantiatedTypes = new Set<DartType>(),
                staticFunctionsNeedingGetter = new Set<FunctionElement>(),
                invokedNames = new Map<SourceString, Set<Selector>>(),
                invokedGetters = new Map<SourceString, Set<Selector>>(),