[lld] [llvm] DTLTO Cache optimization - rebased (PR #203971)

[Teresa Johnson via llvm-commits]

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@@ -48,6 +48,10 @@ class CachedFileStream {
     return Error::success();
   }
 
+  virtual Error commit(std::unique_ptr<MemoryBuffer> MemBuf) {
+    return Error::success();
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teresajohnson wrote:

ping on this suggestion.

https://github.com/llvm/llvm-project/pull/203971