Fixed up registers in debugserver.

- removed all gaps from the g/G packets
- optimized registers for x86_64 to not send/receive xmm0-xmm15 as well as ymm0-ymm15, now we only send ymm0-15 and xmm0-15 are now pseudo regs
- Fixed x86_64 floating point register gaps
- Fixed x86_64 so that xmm8-xmm15 don't overlap with ymm0-ymm3. This could lead to bad values showing in the debugger and was due to bad register info structure contents
- Fixed i386 so we only send ymm0-ymm7 and xmm0-xmm7 are now pseudo regs.
- Fixed ARM register definitions to not have any gaps
- Fixed it so value registers and invalidation registers are specified using register names which avoid games we had to play with register numbering in the ARM plugin.

llvm-svn: 194302