[llvm] [llvm-cov] Add --debug-info flag to llvm-cov to lookup debug info file. (PR #66798)

[Zequan Wu via llvm-commits]

ZequanWu wrote:

Actually, after thinking again about this. I feel we shouldn't move those unused function names from `__llvm_prf_names` to dwarf debug info. The [reason](https://reviews.llvm.org/D157913#4644619) for doing that was `__llvm_prf_names` is not strippable. However, with debug info correlation enabled for clang coverage, `__llvm_prf_names` will just have unused function names which are not used at runtime so we can make them strippable as same as `__llvm_covmap` and `__llvm_covfun`. llvm-cov could just lookup the unstripped binary for `__llvm_prf_names`.

I plan is to discard this change and restore `__llvm_prf_names` section when debug info correlation enabled with clang coverage. But before that, I want to hear about your opinions before that, @ellishg @petrhosek.



https://github.com/llvm/llvm-project/pull/66798