[LLVM-C] Add bindings to create macro debug info

Summary: The C API doesn't have the bindings to create macro debug information.

Reviewers: whitequark, CodaFi, deadalnix

Reviewed By: whitequark

Subscribers: aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58334

llvm-svn: 373903