dart2js cps: Support function types in 'is' and 'as' operators.

pkg/compiler/lib/src/ssa/builder.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 ssa;
 
 class SsaFunctionCompiler implements FunctionCompiler {
   SsaCodeGeneratorTask generator;
   SsaBuilderTask builder;
   SsaOptimizerTask optimizer;
@@ skipping 3089 matching lines @@
           nestedClosureData.getLocalVariableForClosureField(field);
       assert(capturedLocal != null);
       capturedVariables.add(localsHandler.readLocal(capturedLocal));
     });
 
     TypeMask type =
         new TypeMask.nonNullExact(compiler.functionClass, compiler.world);
     push(new HForeignNew(closureClassElement, type, capturedVariables));
 
     Element methodElement = nestedClosureData.closureElement;
-    if (compiler.backend.methodNeedsRti(methodElement)) {
-      registry.registerClosureWithFreeTypeVariables(methodElement);
-    }
+    registry.registerInstantiatedClosure(methodElement);
   }
 
   visitFunctionDeclaration(ast.FunctionDeclaration node) {
     assert(isReachable);
     visit(node.function);
     LocalFunctionElement localFunction =
         elements.getFunctionDefinition(node.function);
     localsHandler.updateLocal(localFunction, pop());
   }
 
@@ skipping 4988 matching lines @@
     if (unaliased is TypedefType) throw 'unable to unalias $type';
     unaliased.accept(this, builder);
   }
 
   void visitDynamicType(DynamicType type, SsaBuilder builder) {
     JavaScriptBackend backend = builder.compiler.backend;
     ClassElement cls = backend.findHelper('DynamicRuntimeType');
     builder.push(new HDynamicType(type, new TypeMask.exact(cls, classWorld)));
   }
 }