cmd/compile: calls can clobber g on s390x
Because a call may ultimately invoke runtime.setg, we have to assume
that g may be clobbered by any call. All of the other architectures
that use a g register already do this, but it was missing from the
s390x caller save clobber set.
Change-Id: Ia931638d42c44979839f20d71097acf31475f423
Reviewed-on: https://go-review.googlesource.com/92835
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>