[AArch64 NEON] Support poly128_t and implement relevant intrinsic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196887 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64 NEON] Replace fpimm with fpz32 for floating compare with zero.
  This is a small change to be strict. Just want get pattern safer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196889 91177308-0d34-0410-b5e6-96231b3b80d8