[MCJIT] Nuke MachineRelocation and MachineCodeEmitter. Now that the old JIT is
gone they're no longer needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218320 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Teach the new shuffle lowering's blend functionality to use AVX2's
VPBLENDD where appropriate even on 128-bit vectors.

According to Agner's tables, this instruction is significantly higher
throughput (can execute on any port) on Haswell chips so we should
aggressively try to form it when available.

Sadly, this loses our delightful shuffle comments. I'll add those back
for VPBLENDD next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218322 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218324 91177308-0d34-0410-b5e6-96231b3b80d8
Just add a fixme about a possibly faster implementation of some atomic loads on some ARM processors

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218326 91177308-0d34-0410-b5e6-96231b3b80d8