misc/cgo/test: make cgo tests run on AIX

Reviewed-on: https://go-review.googlesource.com/56910

From-SVN: r251182

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-9ff49c64ea6dbb5e08d1fa859b99b06049413279
+28e49825162465172ed706283628bf5cc1996260
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/misc/cgo/test/cthread_unix.c

@@ -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 darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 #include <pthread.h>
 #include "_cgo_export.h"

libgo/misc/cgo/test/issue18146.go

@@ -50,6 +50,8 @@ func test18146(t *testing.T) {
 		nproc = 6
 	case "darwin", "dragonfly", "freebsd", "netbsd", "openbsd":
 		nproc = 7
+	case "aix":
+		nproc = 9
 	}
 	if setNproc {
 		var rlim syscall.Rlimit