[llvm] [DwarfDump] Add new set of line-table-related statistics to llvm-dwarfdump (PR #93289)

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

Do we need any more targeted tests for the stats (for example, exercising the cu-unique-file-id code you added)? llvm/test/tools/llvm-dwarfdump/X86/locstats.ll provides some coverage, maybe that's enough to flag up future changes causing issues. I don't have a strong opinion on this but thought it should be brought up. wdyt?

https://github.com/llvm/llvm-project/pull/93289