Breaks split-require

I just noticed that #43 completely breaks [split-require](https://github.com/goto-bus-stop/split-require). Only `module.exports = whatever` work, but all named exports are dropped. I've created a test case in [my fork](https://github.com/tornqvist/common-shakeify/commit/35895a0305b901498b90957497bf86a3167a2e9d) but am struggling to figure out what's wrong.

I'm not fully familiar with the inner workings of split-require and even less so in combination with common-shakeify, @goto-bus-stop, can you see why this change would break split-require?

_Originally posted by @tornqvist in https://github.com/browserify/common-shakeify/issues/43#issuecomment-1308507112_