[llvm] Make WriteIndexesThinBackend multi threaded (PR #109847)

[Teresa Johnson via llvm-commits]

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@@ -1634,8 +1639,6 @@ class WriteIndexesThinBackend : public ThinBackendProc {
       const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
       MapVector<StringRef, BitcodeModule> &ModuleMap) override {
     StringRef ModulePath = BM.getModuleIdentifier();
-    std::string NewModulePath =
-        getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
 
     if (LinkedObjectsFile) {
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teresajohnson wrote:

Can you add a comment about why this is not in the parallel section below

https://github.com/llvm/llvm-project/pull/109847