Revert "Clusterfuzz identified overflow check needed in dehoisting."

This reverts commit r21708, due to ASAN-reported issue.

TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/318073002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21709 ce2b1a6d-e550-0410-aec6-3dcde31c8c00