Re-apply "Clean up the patch file for the isolate library by introducing a new buitlin library: iso…

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 1895 matching lines @@
 }
 $mainEnsureGetter
 """);
   return "${namer.isolateAccess(isolateMain)}($mainAccess)";
   }
 
   emitMain(CodeBuffer buffer) {
     if (compiler.isMockCompilation) return;
     Element main = compiler.mainApp.find(Compiler.MAIN);
     String mainCall = null;
-    if (compiler.isolateLibrary != null) {
+    if (compiler.hasIsolateSupport()) {
       Element isolateMain =
-        compiler.isolateLibrary.find(Compiler.START_ROOT_ISOLATE);
+        compiler.isolateHelperLibrary.find(Compiler.START_ROOT_ISOLATE);
       mainCall = buildIsolateSetup(buffer, main, isolateMain);
     } else {
       mainCall = '${namer.isolateAccess(main)}()';
     }
     if (!compiler.enableMinification) {
       buffer.add("""
 
 //
 // BEGIN invoke [main].
 //
@@ skipping 174 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].
 """;