[llvm] [DAG] ISD::matchUnaryPredicate / matchUnaryFpPredicate / matchBinaryPredicate - add DemandedElts variant (PR #183013)

[Simon Pilgrim via llvm-commits]

================
@@ -400,7 +405,10 @@ bool ISD::matchBinaryPredicate(
     return false;
 
   EVT SVT = LHS.getValueType().getScalarType();
+  bool IsSplat = ISD::SPLAT_VECTOR == LHS.getOpcode();
----------------
RKSimon wrote:

return true

https://github.com/llvm/llvm-project/pull/183013