runtime: add ppc and s390 to linux 32 bits syscall build constraints for gccgo
Theses are not supported by the go compiler but it may helps porting to gccgo.
This is similar to reverting CL 712740 however unlike reverting:
- it fixes the build tags so that 32 & 64 bits
constraints are complement of each other
- it applies the same changes to os_linux_settime32.go and
os_linux_settime64.go since the four files are the exact same
fix of the same bug to different parts of the codebase.
It does not make sense for them to be different.
Change-Id: I08cdcb07e837a5e06ee6f04b7868a4c57b07dd56
Reviewed-on: https://go-review.googlesource.com/c/go/+/714080 Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>