[llvm] [X86] Lower vXi8 multiplies by constant using PMADDUBSW on SSSE3+ targets (PR #95403)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

This is the breakdown I created for #90748 https://llvm.godbolt.org/z/9361GKrds

https://github.com/llvm/llvm-project/pull/95403