syscall: update routing message support for BSD variants

R=rsc
CC=golang-dev
https://golang.org/cl/4826056
diff --git a/src/pkg/syscall/zsyscall_darwin_amd64.go b/src/pkg/syscall/zsyscall_darwin_amd64.go
index 1ba4c3c..25d8772 100644
--- a/src/pkg/syscall/zsyscall_darwin_amd64.go
+++ b/src/pkg/syscall/zsyscall_darwin_amd64.go
@@ -33,16 +33,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe() (r int, w int, errno int) {
-	r0, r1, e1 := RawSyscall(SYS_PIPE, 0, 0, 0)
-	r = int(r0)
-	w = int(r1)
-	errno = int(e1)
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, errno int) {
 	r0, _, e1 := Syscall(SYS_ACCEPT, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)))
 	fd = int(r0)
@@ -244,6 +234,16 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func pipe() (r int, w int, errno int) {
+	r0, r1, e1 := RawSyscall(SYS_PIPE, 0, 0, 0)
+	r = int(r0)
+	w = int(r1)
+	errno = int(e1)
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func kill(pid int, signum int, posix int) (errno int) {
 	_, _, e1 := Syscall(SYS_KILL, uintptr(pid), uintptr(signum), uintptr(posix))
 	errno = int(e1)