Supress flaky test, lib/mirrors/invocation_fuzz_test/string, on mac debug

Additionally, simplify existing supression on javascript command line engines.

Filed issue 21707 to track the flaky test

Review URL: https://codereview.chromium.org//747363004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41945 260f80e4-7a28-3924-810f-c04153c831b5
Add support for if, while, break, continue to js-cps

Also avoid returning values via fields in CodeGenerator.

R=floitsch@google.com

Review URL: https://codereview.chromium.org//725293004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41946 260f80e4-7a28-3924-810f-c04153c831b5
Fix suppression reorg from revision 41945.

I did not take the multitest selector into account

Review URL: https://codereview.chromium.org//756923002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41947 260f80e4-7a28-3924-810f-c04153c831b5