Parser sync tests for `let` identifiers

R=marja@chromium.org
BUG=

Review URL: https://codereview.chromium.org/385613002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22324 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove GDB JIT hooks from the position recorder.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/385583003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22325 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/bleeding_edge' into bleeding_edge