Support enums in dart2dart.

pkg/compiler/lib/src/dart_backend/backend.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 dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 215 matching lines @@
 
     int totalSize = outputter.assembleProgram(
         libraries: compiler.libraryLoader.libraries,
         instantiatedClasses: compiler.resolverWorld.directlyInstantiatedClasses,
         resolvedElements: compiler.enqueuer.resolution.resolvedElements,
         usedTypeLiterals: usedTypeLiterals,
         postProcessElementAst: postProcessElementAst,
         computeElementAst: computeElementAst,
         shouldOutput: shouldOutput,
         isSafeToRemoveTypeDeclarations: isSafeToRemoveTypeDeclarations,
-        sortElements: sortElements,
+        sortElements: Elements.sortedByPosition,
         mirrorRenamer: mirrorRenamer,
         mainFunction: compiler.mainFunction,
         outputUri: compiler.outputUri);
 
     // Output verbose info about size ratio of resulting bundle to all
     // referenced non-platform sources.
     logResultBundleSizeInfo(
         outputter.libraryInfo.userLibraries,
         outputter.elementInfo.topLevelElements,
         totalSize);
@@ skipping 214 matching lines @@
   result.sort(comparison);
   return result;
 }
 
 compareElements(e0, e1) {
   int result = compareBy((e) => e.library.canonicalUri.toString())(e0, e1);
   if (result != 0) return result;
   return compareBy((e) => e.position.charOffset)(e0, e1);
 }
 
-List<Element> sortElements(Iterable<Element> elements) =>
-    sorted(elements, compareElements);
-
 /// [ConstantCompilerTask] for compilation of constants for the Dart backend.
 ///
 /// Since this task needs no distinction between frontend and backend constants
 /// it also serves as the [BackendConstantEnvironment].
 class DartConstantTask extends ConstantCompilerTask
     implements BackendConstantEnvironment {
   final DartConstantCompiler constantCompiler;
 
   DartConstantTask(Compiler compiler)
     : this.constantCompiler = new DartConstantCompiler(compiler),
@@ skipping 60 matching lines @@
   }
 
   void traceGraph(String title, var irObject) {
     compiler.tracer.traceGraph(title, irObject);
   }
 
   DartTypes get dartTypes => compiler.types;
 
   InternalErrorFunction get internalError => compiler.internalError;
 }