Use better names for closures and static variables.

lib/compiler/implementation/enqueue.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.
 
 class EnqueueTask extends CompilerTask {
   final Enqueuer codegen;
   final Enqueuer resolution;
 
   String get name() => 'Enqueue';
 
@@ skipping 75 matching lines @@
       elements = getCachedElements(element);
     }
     queue.add(new WorkItem(element, elements));
   }
 
   bool canBeRecompiled(Element element) {
     // Only member functions can be recompiled. An exception to this is members
     // of closures. They are processed as part of the enclosing function and not
     // present as a separate element (the call to the closure will be a member
     // function).
-    var closure = const SourceString("Closure");
-    return element.isMember() && element.getEnclosingClass().name != closure;
+    return element.isMember() && !element.getEnclosingClass().isClosure();
   }
 
   void registerRecompilationCandidate(Element element,
                                       [TreeElements elements]) {
     if (!canBeRecompiled(element)) return;
     if (queueIsClosed) {
       compiler.internalErrorOnElement(element, "Work list is closed.");
     }
     recompilationCandidates.add(element, elements);
   }
@@ skipping 207 matching lines @@
   void registerIsCheck(Element element) {
     universe.isChecks.add(element);
   }
 
   void forEach(f(WorkItem work)) {
     while (!queue.isEmpty()) {
       f(queue.removeLast());
     }
   }
 }