- The yaml reader/writer interfaces should be changed to return
an explanatory string if there is an error. The existing error_code
abstraction only works for returning low level OS errors. It does not
work for describing formatting issues.
- We need to design a diagnostics interface. It would be nice to share code
with Clang where possible.
- We need to add more attributes to File. In particular, we need cpu
and OS information (like target triples). We should also provide explicit
support for LLVM IR module flags metadata.