[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: http://llvm.org/svn/llvm-project/cfe/trunk@196750 91177308-0d34-0410-b5e6-96231b3b80d8