Add patch for getting pipe handles

1patches/pipe-handles-helper.patch

@@ -0,0 +1,23 @@
+diff --git a/pipe.go b/pipe.go
+index a2da663..ef933c1 100644
+--- a/pipe.go
++++ b/pipe.go
+@@ -122,6 +122,18 @@ type win32MessageBytePipe struct {
+ 	readEOF     bool
+ }
+ 
++// GetPipeHandle returns the underlying handle of a pipe.
++func GetPipeHandle(f net.Conn) windows.Handle {
++	switch v := f.(type) {
++	case *win32MessageBytePipe:
++		return v.handle
++	case *win32Pipe:
++		return v.handle
++	default:
++		return 0
++	}
++}
++
+ type pipeAddress string
+ 
+ func (f *win32Pipe) LocalAddr() net.Addr {