[llvm] [SDAG] Handle insert_subvector in isKnownNeverNaN (PR #131989)

[Jim Lin via llvm-commits]

================
@@ -5625,6 +5625,9 @@ bool SelectionDAG::isKnownNeverNaN(SDValue Op, bool SNaN, unsigned Depth) const
            (SNaN && !C->getValueAPF().isSignaling());
   }
 
+  if (Op.isUndef())
+    return true;
----------------
tclin914 wrote:

Remove it.

https://github.com/llvm/llvm-project/pull/131989