Pull in r164132 from upstream llvm trunk:
When creating MCAsmBackend pass the CPU string as well. In X86AsmBackend store this and use it to not emit long nops when the CPU is geode which doesnt support them. Fixes PR11212.
Pull in r164133 from upstream clang trunk:
Follow up on llvm r164132.
This should prevent illegal instructions when building world on Geode
CPUs (e.g. Soekris).
MFC after: 3 days