[llvm] [DWARFLinker] Patch DW_AT_LLVM_stmt_sequence in the parallel linker (PR #195388)

[via llvm-commits]

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@@ -100,6 +100,7 @@ void CompileUnit::maybeResetToLoadedStage() {
   Abbreviations.clear();
   OutUnitDIE = nullptr;
   DebugAddrIndexMap.clear();
+  StmtSeqListAttributes.clear();
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alx32 wrote:

Should we also clear this in [`cleanupDataAfterClonning`](https://github.com/llvm/llvm-project/blob/82a229344a9f/llvm/lib/DWARFLinker/Parallel/DWARFLinkerCompileUnit.cpp#L249)? Otherwise the `DIEValue*`s here point into the freed allocator from `cloneAndEmit` for the rest of the CU's life. Nothing reads them today, but seems easy to trip on later.

https://github.com/llvm/llvm-project/pull/195388