[GlobalISel][X86] G_ADD/G_SUB vector legalizer/selector support.

Summary: G_ADD/G_SUB vector legalizer/selector support.

Reviewers: zvi, guyblank

Reviewed By: guyblank

Subscribers: rovka, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D33232

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303345 91177308-0d34-0410-b5e6-96231b3b80d8
17 files changed