add Bun as reserved name

[zth]

https://bun.sh/ adds Bun as global object. This reserves that names to that modules cannot accidentally clash.

[cristianoc]

Never noticed this list before.
What's the effect in practice?

[zth]

That list controls if the emitted JS should prefix all interaction with a module with $$ so that referring to the module does not clash with the globally available object.

For the Bun example, if you had a module called Bun which exports only zero cost externals, things would work fine. But if you also export actual code from that module, and use that code somewhere, ReScript would import that module as Bun in the generated JS, shadowing the globally available Bun.

[cknitt]

@zth Actually js_reserved_map.ml is a generated file, see https://github.com/rescript-lang/rescript-compiler/blob/master/CONTRIBUTING.md#update-js-reserved-keywords-map.

Could you adapt this in a way that your change is not overwritten when regenerating the file?

[zth]

Doh! Yeah I'll have a look at it.

[zth]

#6389