Sporadic build failure fix, cleanups and assorted bugfixes

- Fixed binutils build when bash is the default shell (thanks to Jason Kridner for reporting it).
- Updated example instructions to latest Debian: release bone-debian-7.5-2014-05-14-2gb.img.xz
- Minor fixes to the temporary crt0.S
- Fixed text label printing in disassembler.
- Fixed LBBO assembly error for a burst length of 124. It was misreported as out of range, while in fact it is perfectly valid.
- Added gas test vectors.
- Optimized a little 64bit plus and minus operations in GCC.
- Rebased to latest ToT of GCC and Binutils.

Signed-off-by: Dimitar Dimitrov <dinuxbg@gmail.com>