[llvm] [BOLT][DWARF] Slice .debug_str from the DWP for each CU (PR #159540)

[Alexander Yermolovich via llvm-commits]

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@@ -471,6 +471,11 @@ class DebugStrOffsetsWriter {
     return std::move(StrOffsetsBuffer);
   }
 
+  StringRef bufferStr() {
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ayermolo wrote:

Please add description on new apis.

https://github.com/llvm/llvm-project/pull/159540