Patch 1 of 3 to add to llvm-dwarfdump the ability to measure DWARF
coverage of local variables in terms of source lines, as discussed in
this RFC:
https://discourse.llvm.org/t/rfc-debug-info-coverage-tool-v2/83266)
This patch adds the basic variable coverage implementation. By default,
inlined instances are shown separately (displaying the full inlining
chain). Alternatively, a combined view that averages across all inlined
instances can be returned using `--combine-instances`.
In this patch, we simply print a count of source lines over which each
variable is covered. Later patches in the series will add the comparison
against a baseline.
c838756e2d
