Add check to see if stack pointer is off the stack according to the memory
mappings when rating Linux exploitability.

R=ivanpe@chromium.org

Review URL: https://codereview.chromium.org/1286033002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1487 4c0a9323-5329-0410-9bdc-e9ce6186880e
5 files changed