[llvm] [DLCov] Origin-Tracking: Add debugify support (PR #143594)

[Djordje Todorovic via llvm-commits]

djtodoro wrote:

> @djtodoro I found an error in my changes to the script, which caused a failure in the lit test, so I fixed it in the [latest commit](https://github.com/llvm/llvm-project/pull/143594/commits/5dcfe7498dce415fbeb49433fbd2387ac0241907) - along the way, I appear to have _incidentally_ fixed what I think is an existing error that was baked into the test. Specifically, in the lit test that tests the output for `corrupted.json` against `expected-skipped.html`, I believe that one of the bugs was being incorrectly excluded from the HTML report.
> 
> The reason for this is at line 492, where we initialize `di_loc_bugs` as an empty list; in my changes, I've initialized it (and related variables) from the existing `di_location_bugs` map; as it currently is, if bugs already existed for a given (file,pass) pair, they would be overwritten when we wrote back to the master map later with `di_location_bugs[bugs_file][bugs_pass] = di_loc_bugs`.
> 
> Since this is a driveby fix, and I'm updating the tests anyway, I'd prefer to simply fix error in this PR, if you agree that this is a valid fix - WDYT?

I see. I have nothing against it, thanks a lot for it! LGTM.

https://github.com/llvm/llvm-project/pull/143594