dart2js cps: Support JS_CURRENT_ISOLATE.

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.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_task;
 
 import '../closure.dart' as closurelib;
 import '../closure.dart' hide ClosureScope;
 import '../constants/expressions.dart';
 import '../dart_types.dart';
@@ skipping 3164 matching lines @@
         validateArgumentCount(exactly: 2);
         List<ir.Primitive> arguments = argumentNodes.mapToList(visit);
         return irBuilder.buildStringConcatenation(arguments);
 
       case 'JS_CURRENT_ISOLATE_CONTEXT':
         validateArgumentCount(exactly: 0);
 
         if (!compiler.hasIsolateSupport) {
           // If the isolate library is not used, we just generate code
           // to fetch the current isolate.
-          String name = backend.namer.currentIsolate;
-          return irBuilder.buildForeignCode(js.js.parseForeignJS(name),
-              const <ir.Primitive>[], NativeBehavior.PURE);
+          continue GET_CURRENT_ISOLATE;
         }
         return buildIsolateHelperInvocation('_currentIsolate',
             CallStructure.NO_ARGS);
 
+      GET_CURRENT_ISOLATE: case 'JS_CURRENT_ISOLATE':
+        validateArgumentCount(exactly: 0);
+
+        return irBuilder.buildForeignCode(
+            js.js.parseForeignJS(backend.namer.currentIsolate),
+            const <ir.Primitive>[],
+            NativeBehavior.PURE);
+
       case 'JS_CALL_IN_ISOLATE':
         validateArgumentCount(exactly: 2);
 
         if (!compiler.hasIsolateSupport) {
           ir.Primitive closure = visit(argumentNodes.tail.head);
           return irBuilder.buildCallInvocation(closure, CallStructure.NO_ARGS,
               const <ir.Primitive>[]);
         }
         return buildIsolateHelperInvocation('_callInIsolate',
             CallStructure.TWO_ARGS);
@@ skipping 71 matching lines @@
   }
 
   processSetStatic(ir.SetStatic node) {
     node.body = replacementFor(node.body);
   }
 
   processContinuation(ir.Continuation node) {
     node.body = replacementFor(node.body);
   }
 }