net: sort Makefile entries

R=golang-dev, jsing
CC=golang-dev
https://golang.org/cl/5493058

src/pkg/net/Makefile

@@ -21,14 +21,14 @@ GOFILES=\
 	udpsock.go\
 	unixsock.go\
 
-GOFILES_freebsd=\
+GOFILES_darwin=\
 	dnsclient_unix.go\
 	dnsconfig.go\
 	fd.go\
 	fd_$(GOOS).go\
 	file.go\
 	interface_bsd.go\
-	interface_freebsd.go\
+	interface_darwin.go\
 	iprawsock_posix.go\
 	ipsock_posix.go\
 	lookup_unix.go\
@@ -42,21 +42,21 @@ GOFILES_freebsd=\
 	unixsock_posix.go\
 
 ifeq ($(CGO_ENABLED),1)
-CGOFILES_freebsd=\
+CGOFILES_darwin=\
 	cgo_bsd.go\
 	cgo_unix.go
 else
-GOFILES_freebsd+=cgo_stub.go
+GOFILES_darwin+=cgo_stub.go
 endif
 
-GOFILES_darwin=\
+GOFILES_freebsd=\
 	dnsclient_unix.go\
 	dnsconfig.go\
 	fd.go\
 	fd_$(GOOS).go\
 	file.go\
 	interface_bsd.go\
-	interface_darwin.go\
+	interface_freebsd.go\
 	iprawsock_posix.go\
 	ipsock_posix.go\
 	lookup_unix.go\
@@ -70,11 +70,11 @@ GOFILES_darwin=\
 	unixsock_posix.go\
 
 ifeq ($(CGO_ENABLED),1)
-CGOFILES_darwin=\
+CGOFILES_freebsd=\
 	cgo_bsd.go\
 	cgo_unix.go
 else
-GOFILES_darwin+=cgo_stub.go
+GOFILES_freebsd+=cgo_stub.go
 endif
 
 GOFILES_linux=\