[llvm] [llvm-dwarfdump][LineCov 1/3] Add variable coverage metrics (PR #176725)

[J. Ryan Stinnett via llvm-commits]

jryans wrote:

I'll go ahead and merge this now (since it already had lots of review time in the previous round). Hopefully it will stick this time. :smile: 

https://github.com/llvm/llvm-project/pull/176725