Fix build on Android - put the missing NT_GNU_BUILD_ID #define in elf_gnu_compat.h and use it where needed.
Review URL: https://breakpad.appspot.com/554004

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1146 4c0a9323-5329-0410-9bdc-e9ce6186880e