TextDecoder is missing x-user-defined encoding

[ChALkeR]

It should be there per spec

It's a simple single-byte encoding despite its name

Can be treated as a single-byte or algorithmic

Spec: https://encoding.spec.whatwg.org/#x-user-defined-decoder

The usecase for that is old compat loading of binary data over strings, as it can be then decoded easily (and TextDecoder does not expose isomporhic, and latin1 maps to windows1252 and is actually non-isomporhic and complex to decode back to bytes).

[JosephDoUrden]

I’ll take a look at this and report back shortly