[llvm] Add option to dump IR to files instead of stderr (PR #66412)

[Arthur Eubanks via llvm-commits]

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@@ -18,6 +18,7 @@
 #include "llvm/Analysis/CallGraphSCCPass.h"
 #include "llvm/Analysis/LazyCallGraph.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/CodeGen/StableHashing.h"
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aeubanks wrote:

we should pull `StableHashing.h` out of `CodeGen` first

https://github.com/llvm/llvm-project/pull/66412