[AArch64 NEON] Fix pattern match failed on FP_ROUND from v1f128 to v1f64.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200109 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64 NEON] Add test case for vector FP_ROUND.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200110 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64 NEON] Add patterns for concat_vector on v2i32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200111 91177308-0d34-0410-b5e6-96231b3b80d8