[llvm] [BOLT][DWARF][NFC] Fix DebugStrOffsetsWriter (PR #100672)

[Alexander Yermolovich via llvm-commits]

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@@ -503,10 +504,16 @@ class DebugStrOffsetsWriter {
     return StrOffsetSectionWasModified;
   }
 
+  DenseSet<uint64_t> &getDebugStrOffsetsFinalized() {
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ayermolo wrote:

Doesn't look like this is used anymore?

https://github.com/llvm/llvm-project/pull/100672