Clarify effect on module loader cache and module reuse

[mikesamuel]

Host internal caches key on strings to prevent repeated fetching and loading of semantically-equivalent module references. This proposal should not affect or complicate that.

@bmeck, you raised during plenary that implementations often have corner cases around garbage collection with cross-realm GC. Do I understand correctly that this is a concern re module-reference-string-wrapping objects as keys into per-realm caches related to import(moduleReferenceFromAnotherRealm)? Or is that a separable issue?

[bmeck]

This is true, I have lots of docs on this from our node loader work, but would prefer if we could sync up and try and disseminate what the pieces that truly affect the intent of the proposal sometime.