This CL implements the check for rematerializeable value's output
regspec at its remateralization site. It has some potential problems,
please see the TODO in regalloc.go.
Fixes #70451.
Cherry-picked from the dev.simd branch. This CL is not
necessarily SIMD specific. Apply early to reduce risk.
Change-Id: Ib624b967031776851136554719e939e9bf116b7c
Reviewed-on: https://go-review.googlesource.com/c/go/+/695315 Reviewed-by: David Chase <drchase@google.com>
TryBot-Bypass: David Chase <drchase@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/708857 Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>