cmd/compile/internal: intrinsify publicationBarrier on mipsx
This enables publicationBarrier to be used as an intrinsic on mipsx.
Change-Id: Ic199f34b84b3058bcfab79aac8f2399ff21a97ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/674856 Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@google.com>