cmd/compile: adopt strong aux typing for some s390x rules
Convert some optimizations rules to strongly-typed versions. Similar to
CL 230338, this CL only converts rules that need no additional changes
(i.e: only need to change '->' to '=>').
This CL covers the rules from line 800 - 1219.
Passes toolstash-check
Change-Id: I94181a809fa38918b78301f1c0c680b7a8ab552f
Reviewed-on: https://go-review.googlesource.com/c/go/+/230738 Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>