Merged r16224 into 3.20 branch.

Fix invalid out-of-bounds store in MacroAssembler::Allocate.

R=jkummerow@chromium.org
BUG=chromium:263515

Review URL: https://codereview.chromium.org/22980024

git-svn-id: https://v8.googlecode.com/svn/branches/3.20@16263 ce2b1a6d-e550-0410-aec6-3dcde31c8c00