Sub-minor-key-ify HandlerStubs.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/528773002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23566 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Revert "More aggressive reuse of spill slots in the register allocator."

This reverts commit r23536 for breaking DevTools.

TBR=machenbach@chromium.org
BUG=409604
LOG=N

Review URL: https://codereview.chromium.org/527063002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23567 ce2b1a6d-e550-0410-aec6-3dcde31c8c00