Playing sfx stops entire channel until next music pattern
I noticed that playing a sound effect by calling `sfx()` without specifying a channel will stop all music in a channel until the next music pattern. If a game has very fast patterns, it might not be too noticeable. In games with long/slow music patterns though, you definitely notice it. The issue is easy to reproduce in this cart: [Evan the Astronaut 2](https://www.lexaloffle.com/bbs/?tid=45718)

In the real Pico-8 engine, when you get a comet or a planet, you won't really notice a big change in the music since it resumes again right away. However, in fake-08 an entire portion of the music (beat, bass, or melody) will be missing for a good few seconds until the start of the next music pattern.