Implement is-checks for static functions.

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 1233 matching lines @@
 
   void emitStaticFunctionWithNamer(CodeBuffer buffer,
                                    Element element,
                                    CodeBuffer functionBuffer,
                                    String functionNamer(Element element)) {
     String functionName = functionNamer(element);
     buffer.add('$isolateProperties.$functionName$_=$_');
     buffer.add(functionBuffer);
     buffer.add('$N$n');
   }
+
   void emitStaticFunctionsWithNamer(CodeBuffer buffer,
                                     Map<Element, CodeBuffer> generatedCode,
                                     String functionNamer(Element element)) {
     generatedCode.forEach((Element element, CodeBuffer functionBuffer) {
       if (!element.isInstanceMember() && !element.isField()) {
         emitStaticFunctionWithNamer(
             buffer, element, functionBuffer,functionNamer);
       }
     });
   }
@@ skipping 22 matching lines @@
       String invocationName = namer.instanceMethodName(callElement);
       String fieldAccess = '$isolateProperties.$staticName';
       buffer.add("$fieldAccess.$invocationName$_=$_$fieldAccess$N");
       addParameterStubs(callElement, (String name, CodeBuffer value) {
         buffer.add('$fieldAccess.$name$_=$_$value$N');
       });
       // If a static function is used as a closure we need to add its name
       // in case it is used in spawnFunction.
       String fieldName = namer.STATIC_CLOSURE_NAME_NAME;
       buffer.add('$fieldAccess.$fieldName$_=$_"$staticName"$N');
+      for (TypedefElement typedef in checkedTypedefs) {
+        FunctionType typedefType =
+            typedef.computeType(compiler).unalias(compiler);
+        if (compiler.types.isSubtype(element.computeType(compiler),
+                                     typedefType)) {
+          String operator = namer.operatorIs(typedef);
+          buffer.add('$fieldAccess.$operator$_=${_}true$N');
+        }
+      }
     }
   }
 
   void emitBoundClosureClassHeader(String mangledName,
                                    String superName,
                                    List<String> fieldNames,
                                    CodeBuffer buffer) {
     buffer.add('$classesCollector.$mangledName$_=$_'
                '{"":"$superName;${Strings.join(fieldNames,',')}",');
   }
@@ skipping 713 matching lines @@
 """;
 const String HOOKS_API_USAGE = """
 // 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].
 """;