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

pkg/compiler/lib/src/cps_ir/cps_ir_builder.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 dart2js.ir_builder;
 
 import '../compile_time_constants.dart' show BackendConstantEnvironment;
 import '../constants/constant_system.dart';
 import '../constants/expressions.dart';
 import '../constants/values.dart' show ConstantValue, PrimitiveConstantValue;
@@ skipping 2315 matching lines @@
       });
       arguments = new List<ir.Primitive>.from(arguments)
           ..addAll(typeArguments);
     }
     return _continueWithExpression(
         (k) => new ir.InvokeConstructor(type, element, selector,
             arguments, k));
   }
 
   ir.Primitive buildTypeExpression(DartType type) {
+    type = program.unaliasType(type);
     if (type is TypeVariableType) {
       return buildTypeVariableAccess(type);
-    } else if (type is InterfaceType) {
+    } else if (type is InterfaceType || type is FunctionType) {
       List<ir.Primitive> arguments = <ir.Primitive>[];
       type.forEachTypeVariable((TypeVariableType variable) {
         ir.Primitive value = buildTypeVariableAccess(variable);
         arguments.add(value);
       });
       return addPrimitive(new ir.TypeExpression(type, arguments));
     } else if (type.treatAsDynamic) {
       return buildNullConstant();
     } else {
       // TypedefType can reach here, and possibly other things.
@@ skipping 41 matching lines @@
     return addPrimitive(new ir.CreateInvocationMirror(selector, arguments));
   }
 
   @override
   ir.Primitive buildTypeOperator(ir.Primitive value,
                                  DartType type,
                                  {bool isTypeTest}) {
     assert(isOpen);
     assert(isTypeTest != null);
 
+    type = program.unaliasType(type);
+
     if (type.isMalformed) {
       FunctionElement helper = program.throwTypeErrorHelper;
       ErroneousElement element = type.element;
       ir.Primitive message = buildStringConstant(element.message);
       return buildStaticFunctionInvocation(
           helper,
           CallStructure.ONE_ARG,
           <ir.Primitive>[message]);
     }
 
     List<ir.Primitive> typeArguments = const <ir.Primitive>[];
     if (type is GenericType && type.typeArguments.isNotEmpty) {
       typeArguments = type.typeArguments.map(buildTypeExpression).toList();
     } else if (type is TypeVariableType) {
       typeArguments = <ir.Primitive>[buildTypeVariableAccess(type)];
+    } else if (type is FunctionType) {
+      typeArguments = <ir.Primitive>[buildTypeExpression(type)];
     }
 
     if (isTypeTest) {
       // For type tests, we must treat specially the rare cases where `null`
       // satisfies the test (which otherwise never satisfies a type test).
       // This is not an optimization: the TypeOperator assumes that `null`
       // cannot satisfy the type test unless the type is a type variable.
       if (type.isObject || type.isDynamic) {
         // `x is Object` and `x is dynamic` are always true, even if x is null.
         return buildBooleanConstant(true);
@@ skipping 94 matching lines @@
   final DartType type;
   final LocalVariableElement exceptionVariable;
   final LocalVariableElement stackTraceVariable;
   final SubbuildFunction buildCatchBlock;
 
   CatchClauseInfo({this.type,
                    this.exceptionVariable,
                    this.stackTraceVariable,
                    this.buildCatchBlock});
 }