Orthogonalize Lithium binary op instructions.

BUG=
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/23703014

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16739 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add mutex when accessing concurrent recompilation output queue.

Also small refactorings.

R=mstarzinger@chromium.org
BUG=291236

Review URL: https://codereview.chromium.org/23902033

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16740 ce2b1a6d-e550-0410-aec6-3dcde31c8c00