[x86 asm] allow fwait alias in both At&t and Intel modes (PR21208)

Differential Revision: http://reviews.llvm.org/D5741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219725 91177308-0d34-0410-b5e6-96231b3b80d8
[FastISel][AArch64] Add custom lowering for GEPs.

This is mostly a copy of the existing FastISel GEP code, but on AArch64 we bail
out even for simple cases, because the standard fastEmit functions don't cover
MUL and ADD is lowered inefficientily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219726 91177308-0d34-0410-b5e6-96231b3b80d8