[clang] [CIR] Call code gen; create empty cir.func op (PR #113483)

[David Olsen via cfe-commits]

dkolsen-pgi wrote:

> Does https://mlir.llvm.org/docs/Dialects/Builtin/#fusedloc suit the situation [of recording locations of macro expansions]?

Maybe?  Right now I think `FusedLoc` is used by ClangIR to represent a source range.  Maybe it also could be used for macro expansion locations.  I don't if there is a `FusedLoc` metadata convention for that.

That would be something we want to explore and implement in the ClangIR incubator project first.  It's not something I want to implement as part of an upstreaming change.


https://github.com/llvm/llvm-project/pull/113483