- Make array immutable first, then canonicalize it.
- When serializing canonical objects, then inline the referenced
  objects, so that you can canonicalize them when deserializing.
- Reenabled language/enum_const_test.

R=asiva@google.com

Review URL: https://codereview.chromium.org//745203002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41881 260f80e4-7a28-3924-810f-c04153c831b5
Revert revision 41861 "Cleanup API of StdioServerSocket to prevent users from passing in a non-null package root."

This is causing compilation failures:
 http://build.chromium.org/p/client.dart/builders/analyzer_experimental-linux-release-be/builds/413/steps/build/logs/stdio

Review URL: https://codereview.chromium.org//751503002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41882 260f80e4-7a28-3924-810f-c04153c831b5
- Add needed enum flags for dart2js.

Review URL: https://codereview.chromium.org//740383004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41883 260f80e4-7a28-3924-810f-c04153c831b5