adds the security cookie check hook transform.

This transform redirects the __report_gsfailure function to a code-block
that crashes the process with an exception an EH can catch
('mov [deadbeef], 0'). This is particularly useful for fuzzers using
an exception handler in the target to monitor for crashes
(__report_gsfailure triggers an exception that can't be caught with an
EH).

BUG=
R=chrisha@chromium.org

Review-Url: https://codereview.chromium.org/2871863002
4 files changed