[llvm] [DLCov][NFC] Propagate annotated DebugLocs through transformations (PR #138047)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -142,6 +142,31 @@ namespace llvm {
     static inline DebugLoc getDropped() { return DebugLoc(); }
 #endif // LLVM_ENABLE_DEBUGLOC_COVERAGE_TRACKING
 
+    static DebugLoc getMergedLocations(ArrayRef<DebugLoc> Locs);
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OCHyams wrote:

Do these need comments explaining a) what they do and b) how they differ from DILocation::getMergedWhatever? I think updating the latter function's comment too would be helpful, pointing out when it's appropriate to use the other in both cases?

https://github.com/llvm/llvm-project/pull/138047