Exported type information

[xmaams]

It would be useful to annotate names for exported types such as aliases, structs, enums, and function signatures for consumption by downstream tools.

1. Would it be best to add this to the generated IR somewhere?
2. Do you think it is appropriate to have a compiler option to generate a C-compatible header file containing exported type definitions?

[teqdruid]

Given that the focus of Kanagawa (the OSS version) is solely to build hardware, I don't think it should be directly producing C headers. So I think option 1 is the best thing to do. This would allow downstream tools (e.g. ESI) to produce the header files. The only addition which would be needed for ESI to produce named type is for Kanagawa to use TypeAliases for named types in its IR output.