Add failing (for dart2js) deferred constant-list test.

R=johnniwinther@google.com

Review URL: https://codereview.chromium.org//652713002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41092 260f80e4-7a28-3924-810f-c04153c831b5
Add concurrent modification check to ListMixin/IterableMixin.reduce.

Add tests of reduce and fold.

BUG= http://dartbug.com/21289
R=ajohnsen@google.com

Review URL: https://codereview.chromium.org//656773002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41093 260f80e4-7a28-3924-810f-c04153c831b5
Add support for source maps in deferred libraries.

BUG= http://dartbug.com/21221
R=johnniwinther@google.com

Review URL: https://codereview.chromium.org//652723002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41094 260f80e4-7a28-3924-810f-c04153c831b5