This is encoded similarly to RLDICL, but can clear the least
significant bits.
Likewise, update the auxint encoding of RLDICL to match those
used by the rotate and mask word ssa opcodes for easier usage
within lowering rules. The RLDICL ssa opcode is not used yet.
Change-Id: I42486dd95714a3e8e2f19ab237a6cf3af520c905
Reviewed-on: https://go-review.googlesource.com/c/go/+/515575 Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Run-TryBot: Paul Murphy <murp@ibm.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>