[NaryReassociate] Add support for Mul instructions

This patch extends the current pass by handling
Mul instructions as well.

Patch by: Volkan Keles (vkeles@apple.com)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247705 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed