Don't force TextDe/Encoder

[daxpedda]

Currently the generated JS shim calls TextDe/Encoder, even if it's not required by the user.
This forces users to provide a polyfill even when not needed.
Even if just a stub is provided as a polyfill, like done in the wasm-audio-worklet example, it would still require the class TextDe/Encoder to be defined, which prevents support detection by downstream users.

This adjust calls to TextDe/Encoder to do nothing if it's not available.
I don't think this has any use-case outside audio worklets.
This doesn't prevent users from using an actual polyfill if desired.

Cc @lukaslihotzki.
Fixes #2367.

[Liamolucko]

Thanks!

[BlinkyStitt]

So I agree that TextDe/Encoder isn't needed outside of audio worklets, but your diff here removed the code from audio worklets where I do need it. Was that intentional? What is the best way to get this polyfilled inside of an Audio worklet?

78421dc#diff-07cf5528c3f9b4e22f2489de3616bd3ec5adbfeea002b3cad8d7f9d9cd5c68b0

[daxpedda]

It was intentional indeed, as its not required anymore to get audio worklets to run.

Using the usual Worklet.addModule() beforehand should perfectly suffice to inject any polyfill.

In general though I would recommend against using it in audio worklets, as any kind of memory allocation inside the audio worklet can cause stuttering among other issues, which is why the API was removed there to begin with. See WebAudio/web-audio-api#2499 (comment) for more information.