When checking for a wrap take into account offset of the start address in the region.

BUG=http://crbug.com/94425
TEST=test/mjsunit/regress/regress-94425.js
Review URL: http://codereview.chromium.org/7779037

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9145 ce2b1a6d-e550-0410-aec6-3dcde31c8c00