cmd/compile: add PPC64-specific inlining for runtime.memmove
Add rule to PPC64.rules to inline runtime.memmove in more cases, as is
done for other target architectures
Updated tests in codegen/copy.go to verify changes are done on
ppc64/ppc64le
Updates #41662
Change-Id: Id937ce21f9b4f4047b3e66dfa3c960128ee16a2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/352054
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Lynn Boger <laboger@linux.vnet.ibm.com>