New Issue: Support renaming extern types

18173, "bradcray", "Support renaming extern types", "2021-08-06T17:38:15Z"

Most Chapel extern declarations support a means of giving the C name of the symbol a separate identifier from the Chapel name, which is particularly useful with the C name isn't a legal Chapel identifier. For instance:

extern "domain" var c_domain: c_int;

However, it appears that extern type declarations don't support this today. I think they should for completeness and orthogonality, and that this is just an oversight / a case that nobody has tackled yet. I also believe this would be a relatively straightforward project for someone new to the code base and interested in modifying the compiler (and would be happy to advise / assist).