syscall: make signature of Umask on OS X, FreeBSD match Linux.

R=rsc
CC=golang-dev
https://golang.org/cl/207071

src/pkg/syscall/syscall_darwin.go

@@ -552,7 +552,7 @@ func Kill(pid int, signum int) (errno int) { return kill(pid, signum, 1) }
 //sys	Symlink(path string, link string) (errno int)
 //sys	Sync() (errno int)
 //sys	Truncate(path string, length int64) (errno int)
-//sys	Umask(newmask int) (errno int)
+//sys	Umask(newmask int) (oldmask int)
 //sys	Undelete(path string) (errno int)
 //sys	Unlink(path string) (errno int)
 //sys	Unmount(path string, flags int) (errno int)

src/pkg/syscall/syscall_freebsd.go

@@ -549,7 +549,7 @@ func SysctlUint32(name string) (value uint32, errno int) {
 //sys	Symlink(path string, link string) (errno int)
 //sys	Sync() (errno int)
 //sys	Truncate(path string, length int64) (errno int)
-//sys	Umask(newmask int) (errno int)
+//sys	Umask(newmask int) (oldmask int)
 //sys	Undelete(path string) (errno int)
 //sys	Unlink(path string) (errno int)
 //sys	Unmount(path string, flags int) (errno int)

src/pkg/syscall/zsyscall_darwin_386.go

@@ -623,9 +623,9 @@ func Truncate(path string, length int64) (errno int) {
 	return
 }
 
-func Umask(newmask int) (errno int) {
-	_, _, e1 := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
-	errno = int(e1)
+func Umask(newmask int) (oldmask int) {
+	r0, _, _ := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
+	oldmask = int(r0)
 	return
 }
 

src/pkg/syscall/zsyscall_darwin_amd64.go

@@ -623,9 +623,9 @@ func Truncate(path string, length int64) (errno int) {
 	return
 }
 
-func Umask(newmask int) (errno int) {
-	_, _, e1 := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
-	errno = int(e1)
+func Umask(newmask int) (oldmask int) {
+	r0, _, _ := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
+	oldmask = int(r0)
 	return
 }
 

src/pkg/syscall/zsyscall_freebsd_386.go

@@ -623,9 +623,9 @@ func Truncate(path string, length int64) (errno int) {
 	return
 }
 
-func Umask(newmask int) (errno int) {
-	_, _, e1 := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
-	errno = int(e1)
+func Umask(newmask int) (oldmask int) {
+	r0, _, _ := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
+	oldmask = int(r0)
 	return
 }
 

src/pkg/syscall/zsyscall_freebsd_amd64.go

@@ -623,9 +623,9 @@ func Truncate(path string, length int64) (errno int) {
 	return
 }
 
-func Umask(newmask int) (errno int) {
-	_, _, e1 := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
-	errno = int(e1)
+func Umask(newmask int) (oldmask int) {
+	r0, _, _ := Syscall(SYS_UMASK, uintptr(newmask), 0, 0)
+	oldmask = int(r0)
 	return
 }