[PowerPC] Exploit the High Order Vector Multiply Instructions on Power10

This patch aims to exploit the following vector multiply high instructions on Power10.
vmulhsw VRT, VRA, VRB
vmulhsd VRT, VRA, VRB
vmulhuw VRT, VRA, VRB
vmulhud VRT, VRA, VRB

Differential Revision: https://reviews.llvm.org/D82584