Turn mark deoptimize on undefined into a proper HPhase.

This patch also removes the implicit recursion on phi operands,
using a loop and a worklist instead, to avoid potential stack
overflows.

R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/21065003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15952 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Reland initial bits of "Implement correct OS and CC detection."

This adds the OS and CC detection and cleans up the globals.h to
some degree. It also places all of the C++11 feature detection into
globals.h.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/21223003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15953 ce2b1a6d-e550-0410-aec6-3dcde31c8c00