cmd/compile/internal/ssa: cleanup ANDCCconst rewrite rules on PPC64
Avoid creating duplicate usages of ANDCCconst. This is preparation for
a patch to reintroduce ANDconst to simplify the lower pass while
treating ANDCCconst like other *CC* ssa opcodes.
Also, move many of the similar rules wich retarget ANDCCconst users
to the flag result to a common rule for all compares against zero.
Change-Id: Ida86efe17ff413cb82c349d8ef69d2899361f4c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/585400 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>