[AArch64]Pattern match failures for truncate store and extend load


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196748 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64]Add missing pair intrinsics such as:
    int32_t vminv_s32(int32x2_t a)
which should be compiled into SMINP Vd.2S,Vn.2S,Vm.2S


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196749 91177308-0d34-0410-b5e6-96231b3b80d8