Revert "Move dart2js from sdk/lib/_internal/compiler to pkg/compiler"

pkg/dart2js_incremental/lib/library_updater.dart

 // Copyright (c) 2014, 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_incremental.library_updater;
 
 import 'dart:async' show
     Future;
 
 import 'dart:convert' show
     UTF8;
 
 import 'package:compiler/compiler.dart' as api;
 
-import 'package:compiler/src/dart2jslib.dart' show
+import 'package:compiler/implementation/dart2jslib.dart' show
     Compiler,
     Script;
 
-import 'package:compiler/src/elements/elements.dart' show
+import 'package:compiler/implementation/elements/elements.dart' show
     Element,
     FunctionElement,
     LibraryElement,
     ScopeContainerElement;
 
-import 'package:compiler/src/scanner/scannerlib.dart' show
+import 'package:compiler/implementation/scanner/scannerlib.dart' show
     EOF_TOKEN,
     PartialClassElement,
     PartialElement,
     PartialFunctionElement,
     Token;
 
-import 'package:compiler/src/source_file.dart' show
+import 'package:compiler/implementation/source_file.dart' show
     StringSourceFile;
 
-import 'package:compiler/src/tree/tree.dart' show
+import 'package:compiler/implementation/tree/tree.dart' show
     ClassNode,
     FunctionExpression,
     NodeList;
 
-import 'package:compiler/src/js/js.dart' show
+import 'package:compiler/implementation/js/js.dart' show
     js;
 
-import 'package:compiler/src/js/js.dart' as jsAst;
+import 'package:compiler/implementation/js/js.dart' as jsAst;
 
-import 'package:compiler/src/js_emitter/js_emitter.dart' show
+import 'package:compiler/implementation/js_emitter/js_emitter.dart' show
     CodeEmitterTask,
     MemberInfo;
 
-import 'package:_internal/compiler/js_lib/shared/embedded_names.dart'
-    as embeddedNames;
+import 'package:compiler/js_lib/shared/embedded_names.dart' as embeddedNames;
 
-import 'package:compiler/src/js_backend/js_backend.dart' show
+import 'package:compiler/implementation/js_backend/js_backend.dart' show
     JavaScriptBackend,
     Namer;
 
 import 'diff.dart' show
     Difference,
     computeDifference;
 
 typedef void Logger(message);
 
 typedef bool Reuser(
@@ skipping 322 matching lines @@
     before.getOrSet = after.getOrSet;
   }
 
   /// Reset various caches and remove this element from the compiler's internal
   /// state.
   void reuseElement() {
     compiler.forgetElement(before);
     before.reuseElement();
   }
 }