[llvm] [X86] Generate `vpmuludq` instead of `vpmullq` (PR #121456)

[Phoebe Wang via llvm-commits]

================
@@ -0,0 +1,18 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=x86_64-- -mattr=+avx512dq -O3 | FileCheck %s
----------------
phoebewang wrote:

Do not use `-O3` here.

https://github.com/llvm/llvm-project/pull/121456