[llvm] [DAGCombiner] Enable constant folding of (bitcast int_c0) -> fp_c0 (PR #82289)

[via llvm-commits]

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@@ -15231,8 +15231,7 @@ SDValue DAGCombiner::visitBITCAST(SDNode *N) {
   // TODO: Support FP bitcasts after legalize types.
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goldsteinn wrote:

https://reviews.llvm.org/D58884, adding what I think is the necessary check.

https://github.com/llvm/llvm-project/pull/82289