[llvm] [ValueTracking] Use SimplifyQuery in some public APIs (NFC) (PR #68290)

[via llvm-commits]

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@@ -39,7 +40,6 @@ struct KnownBits;
 class Loop;
 class LoopInfo;
 class MDNode;
-struct SimplifyQuery;
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goldsteinn wrote:

Does LLVM try to adhere to pattern of including minimum number of dependent headers that leaves code compiling? If so would say fwd declare makes more sense.

Otherwise think most people pulling in ValueTracking will also want simplifyquery so leaving in makes sense.

https://github.com/llvm/llvm-project/pull/68290