Fix the bugs about AArch64 Load/Store vector types and bitcast between i64 and vector types.
e.g. "%tmp = load <2 x i64>* %ptr" can't be selected. 
     "%tmp = bitcast i64 %in to <2 x i32>" can't be selected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195424 91177308-0d34-0410-b5e6-96231b3b80d8