Use StringRef::endswith_lower. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193788 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Add support for NEON scalar shift immediate instructions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193791 91177308-0d34-0410-b5e6-96231b3b80d8