Add platform_none for cygwin build

src/platform_none.cc

@@ -0,0 +1,16 @@
+#include "node.h"
+#include "platform.h"
+
+
+namespace node {
+
+
+int OS::GetMemory(size_t *rss, size_t *vsize) {
+  // Not implemented
+  *rss = 0;
+  *vsize = 0;
+  return 0;
+}
+
+
+}  // namespace node