Recommit "[DebugInfo] Refactored macro related generation,

added a test case for macinfo.dwo emission."

This was reverted in caa41209,
since it was causing an assertion failure on Windows bots.
This revision is revised to fix that.

Original commit message -

[DebugInfo] Refactored macro related generation, added a test case for macinfo.dwo emission.

Reviewers: dblaikie, aprantl, jini.susan.george

Tags: #debug-info #llvm

Differential Revision: https://reviews.llvm.org/D71008