cmd/compile: combine similar optimization rules on arm64
This CL combines some rules with the same structure.
In order to avoid extremely long rules, this CL does not merge some
rules. In addition, this CL aligned the components of some rules for
better reading.
Change-Id: I4ba1493251ace00b10591e3c8eef4b6277a4b226
Reviewed-on: https://go-review.googlesource.com/c/go/+/476115
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com> Reviewed-by: Cherry Mui <cherryyz@google.com>