From-SVN: r47173
From-SVN: r46809
* gcc_release: Build snapshots from mainline. Generate Ada and Chill tarballs. Correct error check when building diffs. Check for errors when building bzip2 files. * crontab: Use /sourceware/snapshot-tmp for building snapshots. From-SVN: r46456
* gcc_release: Copy from 3.0 branch. Add support for building the weekly snapshots on gcc.gnu.org. From-SVN: r46073