Support corelib tests in checked mode.

sdk/lib/_internal/compiler/implementation/js_backend/emitter.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;
 
 /**
  * A function element that represents a closure call. The signature is copied
  * from the given element.
  */
@@ skipping 902 matching lines @@
    * Generate "is tests" for [cls]: itself, and the "is tests" for the
    * classes it implements. We don't need to add the "is tests" of the
    * super class because they will be inherited at runtime.
    */
   void generateIsTestsOn(ClassElement cls,
                          void emitIsTest(ClassElement element)) {
     if (checkedClasses.contains(cls)) {
       emitIsTest(cls);
     }
     Set<Element> generated = new Set<Element>();
+    // A class that defines a [:call:] method implicitly implements
+    // [Function].
+    if (checkedClasses.contains(compiler.functionClass)
+        && cls.lookupLocalMember(Compiler.CALL_OPERATOR_NAME) != null) {
+      generateInterfacesIsTests(compiler.functionClass, emitIsTest, generated);
+    }
     for (DartType interfaceType in cls.interfaces) {
       generateInterfacesIsTests(interfaceType.element, emitIsTest, generated);
     }
   }
 
   /**
    * Generate "is tests" where [cls] is being implemented.
    */
   void generateInterfacesIsTests(ClassElement cls,
                                  void emitIsTest(ClassElement element),
@@ skipping 728 matching lines @@
 const String HOOKS_API_USAGE = """
 // Generated by dart2js, the Dart to JavaScript compiler.
 // The code supports the following hooks:
 // dartPrint(message)   - if this function is defined it is called
 //                        instead of the Dart [print] method.
 // dartMainRunner(main) - if this function is defined, the Dart [main]
 //                        method will not be invoked directly.
 //                        Instead, a closure that will invoke [main] is
 //                        passed to [dartMainRunner].
 """;