restore Windows compatibility (#860) (#861)

pkg/readbuffer/read_buffer_other.go

@@ -0,0 +1,10 @@
+//go:build !linux && !windows
+
+package readbuffer
+
+import "fmt"
+
+// ReadBuffer returns the read buffer size.
+func ReadBuffer(pc PacketConn) (int, error) {
+	return 0, fmt.Errorf("read buffer size is unimplemented on the current operating system")
+}