Add PPC64 support to breakpad processor.

A=Jia Ji <jijia@google.com>
Original review: https://breakpad.appspot.com/557002/
Review URL: https://breakpad.appspot.com/558002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1147 4c0a9323-5329-0410-9bdc-e9ce6186880e