Introduce "CommonElements"

tests/compiler/dart2js/memory_compiler.dart

 // Copyright (c) 2016, 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.test.memory_compiler;
 
 import 'dart:async';
 
 import 'package:compiler/compiler.dart' show
     DiagnosticHandler;
@@ skipping 141 matching lines @@
           entryPoint: entryPoint,
           resolutionInputs: resolutionInputs,
           libraryRoot: libraryRoot,
           packageRoot: packageRoot,
           options: options,
           environment: {},
           packageConfig: packageConfig,
           packagesDiscoveryProvider: packagesDiscoveryProvider));
 
   if (cachedCompiler != null) {
-    compiler.coreLibrary =
-        cachedCompiler.libraryLoader.lookupLibrary(Uri.parse('dart:core'));
     compiler.types = cachedCompiler.types.copy(compiler.resolution);
     Map copiedLibraries = {};
     cachedCompiler.libraryLoader.libraries.forEach((library) {
       if (library.isPlatformLibrary) {
         var libraryLoader = compiler.libraryLoader;
         libraryLoader.mapLibrary(library);
         compiler.onLibraryCreated(library);
         compiler.onLibraryScanned(library, null);
         if (library.isPatched) {
           var patchLibrary = library.patch;
           compiler.onLibraryCreated(patchLibrary);
           compiler.onLibraryScanned(patchLibrary, null);
         }
         copiedLibraries[library.canonicalUri] = library;
       }
     });
     // TODO(johnniwinther): Assert that no libraries are loaded lazily from
     // this call.
     compiler.onLibrariesLoaded(new MemoryLoadedLibraries(copiedLibraries));
 
     compiler.backend.constantCompilerTask.copyConstantValues(
         cachedCompiler.backend.constantCompilerTask);
-    compiler.mirrorSystemClass = cachedCompiler.mirrorSystemClass;
-    compiler.mirrorsUsedClass = cachedCompiler.mirrorsUsedClass;
-    compiler.mirrorSystemGetNameFunction =
-        cachedCompiler.mirrorSystemGetNameFunction;
-    compiler.mirrorsUsedConstructor = cachedCompiler.mirrorsUsedConstructor;
-    compiler.deferredLibraryClass = cachedCompiler.deferredLibraryClass;
 
     Iterable cachedTreeElements =
         cachedCompiler.enqueuer.resolution.processedElements;
     cachedTreeElements.forEach((element) {
       if (element.library.isPlatformLibrary) {
         compiler.enqueuer.resolution.registerProcessedElement(element);
       }
     });
 
     // One potential problem that can occur when reusing elements is that there
@@ skipping 52 matching lines @@
       handler = (Uri uri, int begin, int end, String message, Diagnostic kind) {
         diagnosticHandler(uri, begin, end, message, kind);
         formattingHandler(uri, begin, end, message, kind);
       };
     }
   } else if (diagnosticHandler == null) {
     handler = (Uri uri, int begin, int end, String message, Diagnostic kind) {};
   }
   return handler;
 }