Fix overflow check when shifting unboxed mints on 32-bit platforms, except on
MIPS, which does not yet support unboxed mints (work in progress). Issue 21715.
Add regression test.

R=zra@google.com

Review URL: https://codereview.chromium.org//755383002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42003 260f80e4-7a28-3924-810f-c04153c831b5
Fix issue 21426

R=paulberry@google.com

Review URL: https://codereview.chromium.org//757023004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42004 260f80e4-7a28-3924-810f-c04153c831b5
Issue 21706. Fix for Hyperlinking under server.

R=brianwilkerson@google.com
BUG= https://code.google.com/p/dart/issues/detail?id=21706

Review URL: https://codereview.chromium.org//764623002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42005 260f80e4-7a28-3924-810f-c04153c831b5