[llvm] [SelectionDAG] Fix unsafe cases for loop.dependence.{war/raw}.mask (PR #168565)

[Sam Tebbs via llvm-commits]

================
@@ -1692,23 +1699,32 @@ void DAGTypeLegalizer::SplitVecRes_BITCAST(SDNode *N, SDValue &Lo,
   Hi = DAG.getNode(ISD::BITCAST, dl, HiVT, Hi);
 }
 
+/// Split a loop dependence mask.
----------------
SamTebbs33 wrote:

Done.

https://github.com/llvm/llvm-project/pull/168565