[VE] Set getExtendForAtomicOps to ISD::ANY_EXTEND

The implementation of subword atomics does not actually
guarantee the result is zero-extended, which now caused
failures after https://reviews.llvm.org/D101342 was landed.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D106225

lib/Target/VE/VEISelLowering.h

@@ -98,6 +98,9 @@ public:
                                  AtomicOrdering Ord) const override;
   TargetLoweringBase::AtomicExpansionKind
   shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
+  ISD::NodeType getExtendForAtomicOps() const override {
+    return ISD::ANY_EXTEND;
+  }
 
   /// Custom Lower {
   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;