Generate Mach-O in-memory objects for OSX. Dump locals and parameters
for non-optimized frames.

Unfortunately, it seems like more-recent-GDB on OSX there is a little
temperamental (eg, the version from macports will be missing symbols
from gdb-integration_g when the version included in xcode will not--
and this is with --gdbjit off).

Includes some Python scripts to make dealing with V8 values in gdb more
pleasant.

Patch by Luke Zarko.

Review URL: http://codereview.chromium.org/6995161

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8483 ce2b1a6d-e550-0410-aec6-3dcde31c8c00