syscall: fix TestForeground for AIX

Syscall function can't be used on AIX. Therefore, Ioctl in
TestForeground must call raw_ioctl.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/175080

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-99ab98d2ed8fa8a33947c52925f89b344d7cb8ae
+cfee06e20a172753552b1515dd3a4fde5d5cad7b
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/syscall/export_aix_test.go

@@ -0,0 +1,16 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build aix
+
+package syscall
+
+import (
+	"unsafe"
+)
+
+func Ioctl(fd, req, arg uintptr) (err Errno) {
+	_, err = raw_ioctl_ptr(int(fd), req, unsafe.Pointer(arg))
+	return err
+}

libgo/go/syscall/export_unix_test.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.
 
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
+// +build darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 package syscall