[llvm] [AArch64][CodeGen] Fix crash when fptrunc returns fp16 with +nofp attr (PR #81724)

[Nashe Mncube via llvm-commits]

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@@ -25008,6 +25008,16 @@ void AArch64TargetLowering::ReplaceNodeResults(
       Results.push_back(
           LowerToPredicatedOp(SDValue(N, 0), DAG, AArch64ISD::MULHU_PRED));
     return;
+  case ISD::FP_ROUND: {
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nasherm wrote:

My newest patch tries to just default to the generic legalizer when attempting to bitcast with the operand being an fp16. Do let me know your thoughts on this approach

https://github.com/llvm/llvm-project/pull/81724