[wasm] Change the default lowering of stores.

test/unittests/compiler/int64-lowering-unittest.cc

Index: test/unittests/compiler/int64-lowering-unittest.cc
diff --git a/test/unittests/compiler/int64-lowering-unittest.cc b/test/unittests/compiler/int64-lowering-unittest.cc
index 83c8d003dbeeffd8be7ccc6c0dab8f8595ebb550..b55f81908816a0154873a8cc2e37d55dd304d30a 100644
--- a/test/unittests/compiler/int64-lowering-unittest.cc
+++ b/test/unittests/compiler/int64-lowering-unittest.cc
@@ -237,6 +237,38 @@ TEST_F(Int64LoweringTest, Int64Store) {
   INT64_STORE_LOWERING(Store, rep32, rep64);
 }
 
+TEST_F(Int64LoweringTest, Int32Store) {
+  const StoreRepresentation rep32(MachineRepresentation::kWord32,
+                                  WriteBarrierKind::kNoWriteBarrier);
+  int32_t base = 1111;
+  int32_t index = 2222;
+  int32_t return_value = 0x5555;
+
+  Signature<MachineRepresentation>::Builder sig_builder(zone(), 1, 0);
+  sig_builder.AddReturn(MachineRepresentation::kWord32);
+
+  Node* store = graph()->NewNode(machine()->Store(rep32), Int32Constant(base),
+                                 Int32Constant(index), Int64Constant(value(0)),
+                                 start(), start());
+
+  Node* zero = graph()->NewNode(common()->Int32Constant(0));
+  Node* ret = graph()->NewNode(common()->Return(), zero,
+                               Int32Constant(return_value), store, start());
+
+  NodeProperties::MergeControlToEnd(graph(), common(), ret);
+
+  Int64Lowering lowering(graph(), machine(), common(), zone(),
+                         sig_builder.Build());
+  lowering.LowerGraph();
+
+  EXPECT_THAT(
+      graph()->end()->InputAt(1),
+      IsReturn(IsInt32Constant(return_value),
+               IsStore(rep32, IsInt32Constant(base), IsInt32Constant(index),
+                       IsInt32Constant(low_word_value(0)), start(), start()),
+               start()));
+}
+
 TEST_F(Int64LoweringTest, Int64UnalignedStore) {
   const UnalignedStoreRepresentation rep64(MachineRepresentation::kWord64);
   const UnalignedStoreRepresentation rep32(MachineRepresentation::kWord32);