[llvm] [DLCov 1/5] Add CMake option to enable enhanced line number coverage tracking (PR #107278)

[J. Ryan Stinnett via llvm-commits]

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@@ -475,6 +475,17 @@ enabled sub-projects. Nearly all of these variable names begin with
 **LLVM_ENABLE_BINDINGS**:BOOL
   If disabled, do not try to build the OCaml bindings.
 
+**LLVM_ENABLE_DEBUGLOC_COVERAGE_TRACKING**:STRING
+  Enhances Debugify's ability to detect line number errors by storing extra
+  information inside Instructions, removing false positives from Debugify's
+  results at the cost of performance. Allowed values are `DISABLED` (default),
+  `COVERAGE`, and `COVERAGE_AND_ORIGIN`. `COVERAGE` tracks whether and why a
+  line number was intentionally dropped or not generated for an instruction,
+  allowing Debugify to avoid reporting these as errors. `COVERAGE_AND_ORIGIN`
+  additionally stores a stacktrace of the point where each DebugLoc is
----------------
jryans wrote:

```suggestion
  additionally stores a stack trace of the point where each DebugLoc is
```

https://github.com/llvm/llvm-project/pull/107278