Move dart2jslib parts into separate libraries.

pkg/compiler/lib/src/resolution/class_members.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.
 
 library resolution.compute_members;
 
 import '../elements/elements.dart'
     show Element,
          Name,
          PublicName,
          Member,
          MemberElement,
          MemberSignature,
          LibraryElement,
          ClassElement,
          MixinApplicationElement;
 import '../dart_types.dart';
 import '../dart2jslib.dart'
     show Compiler,
-         MessageKind,
          invariant,
          isPrivateName;
+import '../messages.dart' show MessageKind;
 import '../util/util.dart';
 
 part 'member_impl.dart';
 
 abstract class MembersCreator {
   final ClassElement cls;
   final Compiler compiler;
 
   final Iterable<String> computedMemberNames;
   final Map<Name, Member> classMembers;
@@ skipping 871 matching lines @@
         message: "Members have not been fully computed for $this."));
     if (interfaceMembersAreClassMembers) {
       classMembers.forEach((_, member) {
         if (!member.isStatic) f(member);
       });
     } else {
       interfaceMembers.forEach((_, member) => f(member));
     }
   }
 }