runtime: maybe fix Windows build broken by cgo setenv CL

R=rsc
CC=golang-dev
https://golang.org/cl/4428078

src/pkg/runtime/cgo/Makefile

@@ -28,18 +28,20 @@ CGO_OFILES=\
 	$(GOOS)_$(GOARCH).o\
 	util.o\
 
-OFILES=\
-	iscgo.$O\
-	callbacks.$O\
-	_cgo_import.$O\
-	$(CGO_OFILES)\
-
 ifeq ($(GOOS),windows)
 CGO_LDFLAGS=-lm -mthreads
 else
 CGO_LDFLAGS=-lpthread
+CGO_OFILES+=setenv.o\
+
 endif
 
+OFILES=\
+	iscgo.$O\
+	callbacks.$O\
+	_cgo_import.$O\
+	$(CGO_OFILES)\
+
 ifeq ($(GOOS),freebsd)
 OFILES+=\
 	freebsd.$O\

src/pkg/runtime/cgo/setenv.c

+// Copyright 20111 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "libcgo.h"
+
+#include <stdlib.h>
+
+/* Stub for calling setenv */
+static void
+xlibcgo_setenv(char **arg)
+{
+	setenv(arg[0], arg[1], 1);
+}
+
+void (*libcgo_setenv)(char**) = xlibcgo_setenv;

src/pkg/runtime/cgo/util.c

@@ -4,8 +4,6 @@
 
 #include "libcgo.h"
 
-#include <stdlib.h>
-
 /* Stub for calling malloc from Go */
 static void
 x_cgo_malloc(void *p)
@@ -51,12 +49,3 @@ xlibcgo_thread_start(ThreadStart *arg)
 }
 
 void (*libcgo_thread_start)(ThreadStart*) = xlibcgo_thread_start;
-
-/* Stub for calling setenv */
-static void
-xlibcgo_setenv(char **arg)
-{
-	setenv(arg[0], arg[1], 1);
-}
-
-void (*libcgo_setenv)(char**) = xlibcgo_setenv;