[globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541
Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson
Reviewed By: aemerson
Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D45543
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331816 91177308-0d34-0410-b5e6-96231b3b80d8
12 files changed