[release-branch.go1.24] cmd/compile: ensure we don't reuse temporary register
Before this CL, we could use the same register for both a temporary
register and for moving a value in the output register out of the way.
Fixes #71904
Change-Id: Iefbfd9d4139136174570d8aadf8a0fb391791ea9
Reviewed-on: https://go-review.googlesource.com/c/go/+/651221
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
(cherry picked from commit
cc16fb52e6f1eafaee468f8563525ec391e016f5)
Reviewed-on: https://go-review.googlesource.com/c/go/+/652178