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>

src/runtime/os_linux_futex32.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && (386 || arm || mips || mipsle)
+//go:build linux && (386 || arm || mips || mipsle || (gccgo && (ppc || s390)))
 
 package runtime
 

src/runtime/os_linux_futex64.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !(386 || arm || mips || mipsle)
+//go:build linux && !(386 || arm || mips || mipsle || (gccgo && (ppc || s390)))
 
 package runtime
 

src/runtime/os_linux_settime32.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && (386 || arm || mips || mipsle)
+//go:build linux && (386 || arm || mips || mipsle || (gccgo && (ppc || s390)))
 
 package runtime
 

src/runtime/os_linux_settime64.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !(386 || arm || mips || mipsle)
+//go:build linux && !(386 || arm || mips || mipsle || (gccgo && (ppc || s390)))
 
 package runtime