windows: fix netchan test by using 127.0.0.1.

Re-enable the test on Windows.

R=brainman, alex.brainman
CC=golang-dev
https://golang.org/cl/2244041

src/pkg/Makefile

@@ -189,7 +189,6 @@ endif
 # Disable tests that windows cannot run yet.
 ifeq ($(GOOS),windows)
 NOTEST+=exec         # no pipe
-NOTEST+=netchan      # net.Dial("tcp", "", "0.0.0.0:80") doesn't work on windows
 NOTEST+=os           # many things unimplemented
 NOTEST+=os/signal    # no signals
 NOTEST+=path         # tree walking does not work

src/pkg/netchan/netchan_test.go

@@ -151,7 +151,7 @@ type value struct {
 
 // This test cross-connects a pair of exporter/importer pairs.
 func TestCrossConnect(t *testing.T) {
-	e1, err := NewExporter("tcp", ":0")
+	e1, err := NewExporter("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal("new exporter:", err)
 	}
@@ -160,7 +160,7 @@ func TestCrossConnect(t *testing.T) {
 		t.Fatal("new importer:", err)
 	}
 
-	e2, err := NewExporter("tcp", ":0")
+	e2, err := NewExporter("tcp", "127.0.0.1:0")
 	if err != nil {
 		t.Fatal("new exporter:", err)
 	}