[ARM] Add codegen for SMMULR, SMMLAR and SMMLSR

This patch teaches the Arm back-end to generate the SMMULR, SMMLAR and SMMLSR
instructions from equivalent IR patterns.

Differential Revision: https://reviews.llvm.org/D41775


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322361 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed