[llvm] [PatternMatch] Add a matching helper `m_ElementWiseBitCast`. NFC. (PR #80764)

[Matt Arsenault via llvm-commits]

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@@ -2382,7 +2382,8 @@ static Instruction *foldSelectToCopysign(SelectInst &Sel,
   const APInt *C;
   bool IsTrueIfSignSet;
   ICmpInst::Predicate Pred;
-  if (!match(Cond, m_OneUse(m_ICmp(Pred, m_BitCast(m_Value(X)), m_APInt(C)))) ||
+  if (!match(Cond, m_OneUse(m_ICmp(Pred, m_ElementWiseBitCast(m_Value(X)),
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arsenm wrote:

shouldn't there be some deleted checks here now?

https://github.com/llvm/llvm-project/pull/80764