Fix @genType issue with module aliases

[cristianoc]

See #6112
When module aliases module A = B are used, the aliasing information is lost if it happens in another file. There's enough logic to adapt the type export in the presence of module aliases. However this works locally, but not in a file that has no type exports and only a module alias.

This PR:

• allows @genType at the leve of modules
• expands B in module A = B

[cristianoc]

There are a couple of ways one could try to handle this:

1. special-case module aliases, and go past them (consistent with e.g. jump to location in the editor)
2. allow module-level @genType annotations and add one to the module alias

[cristianoc]

@jmagaram would you take a look at this? Notice I changed Wrapper.res to add an include:

@genType
module MyModuleAlias = {include MyModule}

This should take care of your examples, but still worth double checking.

If this works, I will separately look into making in unnecessary to use the include, which can be expensive.

[jmagaram]

Yes. I think if you look at my comments in the original issue you can see I suggested that as a possible solution. It is essentially rewriting the whole module in a different place.

…

________________________________ From: Cristiano Calcagno ***@***.***> Sent: Friday, April 7, 2023 7:25:36 PM To: rescript-lang/rescript-compiler ***@***.***> Cc: Justin Magaram ***@***.***>; Mention ***@***.***> Subject: Re: [rescript-lang/rescript-compiler] WIP: Demonstrate @genType issue with module aliases (PR #6113) @jmagaram<https://github.com/jmagaram> would you take a look at this? Notice I changed the wrapper to add an include: @genType module MyModuleAlias = {include MyModule} This should take care of your examples, but still worth double checking. If this works, I will separately look into making in unnecessary to use the include, which can be expensive. — Reply to this email directly, view it on GitHub<#6113 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ADLZYSZX6OA6RRGJ2VURUTTXADECBANCNFSM6AAAAAAWUYMUPI>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[cristianoc]

Yes. I think if you look at my comments in the original issue you can see I suggested that as a possible solution. It is essentially rewriting the whole module in a different place.
…

Great.
We don't want to rely on include, so next I'll look into how to remove it.

[cristianoc]

@jmagaram take a look now. This is ready for another set of testing.
While the example discussed seems to work, it does not hurt to try a few variations. And also watch for any unintended consequences.

Base on this PR, the way to go is to annotate the aliasing:

@genType
module A = B