[llvm] [DebugInfo] Assign best possible debugloc to bundle (PR #164573)

[Orlando Cazalet-Hyams via llvm-commits]

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@@ -83,15 +83,20 @@ llvm::createUnpackMachineBundles(
   return new UnpackMachineBundles(std::move(Ftor));
 }
 
-/// Return the first found DebugLoc that has a DILocation, given a range of
-/// instructions. The search range is from FirstMI to LastMI (exclusive). If no
-/// DILocation is found, then an empty location is returned.
+/// Return the first good DebugLoc that has line number information, given a
+/// range of instructions. The search range is from FirstMI to LastMI
+/// (exclusive). If no such DebugLoc is found, get the one with DILocation
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OCHyams wrote:

```suggestion
/// Return the first DebugLoc that has line number information, given a
/// range of instructions. The search range is from FirstMI to LastMI
/// (exclusive). Otherwise return the first DILocation or an empty location if
/// there are none.
```

nit: I think the term "good" could be ambiguous and we could be a bit more precise about what's happening

https://github.com/llvm/llvm-project/pull/164573