[X86] Make Feature64Bit useful
We now only add +64bit to the CPU string for "generic" CPU. All other CPU names are assumed to have the feature flag already set if they support 64-bit. I've remove the implies from CMPXCHG8 so that Feature64Bit only comes in via CPUs or user passing -mattr=+64bit.
I've changed the assert to a report_fatal_error so it's not lost in Release builds.
The test updates are to fix things that tripped the new error.
Differential Revision: https://reviews.llvm.org/D51231
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341022 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed