[llvm] Add hash-backed print-changed modes (PR #204490)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,53 @@
+; RUN: opt -S -passes=instsimplify -print-changed=quiet,hash 2>&1 \
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arsenm wrote:

-disable-output instead of -o /dev/null

https://github.com/llvm/llvm-project/pull/204490