Support type variables as expressions.

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

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 1010 matching lines @@
     enqueueInResolution(getGetRuntimeTypeArgument());
   }
 
   void registerRuntimeType() {
     enqueueInResolution(getSetRuntimeTypeInfo());
     enqueueInResolution(getGetRuntimeTypeInfo());
     enqueueInResolution(getGetRuntimeTypeArgument());
     compiler.enqueuer.resolution.registerInstantiatedClass(compiler.listClass);
   }
 
+  void registerTypeVariable() {
+    registerRuntimeType();
+    enqueueInResolution(getRuntimeTypeToString());
+    enqueueInResolution(getCreateRuntimeType());
+  }
+
   void registerIsCheck(DartType type, Enqueuer world) {
     bool isTypeVariable = type.kind == TypeKind.TYPE_VARIABLE;
     if (!type.isRaw || isTypeVariable) {
       enqueueInResolution(getSetRuntimeTypeInfo());
       enqueueInResolution(getGetRuntimeTypeInfo());
       enqueueInResolution(getGetRuntimeTypeArgument());
       enqueueInResolution(getCheckArguments());
       if (isTypeVariable) enqueueInResolution(getGetObjectIsSubtype());
       world.registerInstantiatedClass(compiler.listClass);
     }
@@ skipping 439 matching lines @@
   }
 
   Element getGetRuntimeTypeInfo() {
     return compiler.findHelper(const SourceString('getRuntimeTypeInfo'));
   }
 
   Element getGetRuntimeTypeArgument() {
     return compiler.findHelper(const SourceString('getRuntimeTypeArgument'));
   }
 
+  Element getRuntimeTypeToString() {
+    return compiler.findHelper(const SourceString('runtimeTypeToString'));
+  }
+
   Element getCheckArguments() {
     return compiler.findHelper(const SourceString('checkArguments'));
   }
 
   Element getGetObjectIsSubtype() {
     return compiler.findHelper(const SourceString('objectIsSubtype'));
   }
 
   Element getThrowNoSuchMethod() {
     return compiler.findHelper(const SourceString('throwNoSuchMethod'));
@@ skipping 25 matching lines @@
     assert(invariant(element, element.isDeclaration));
     generatedCode.remove(element);
     generatedBailoutCode.remove(element);
     compiler.enqueuer.codegen.addToWorkList(element);
   }
 
   bool isNullImplementation(ClassElement cls) {
     return cls == jsNullClass;
   }
 }