[builtins] Fix Generate_AtomicsStore.

src/builtins/builtins-sharedarraybuffer.cc

Index: src/builtins/builtins-sharedarraybuffer.cc
diff --git a/src/builtins/builtins-sharedarraybuffer.cc b/src/builtins/builtins-sharedarraybuffer.cc
index cd9dc07e0c6eb8ca2561ab351123ccd959b91712..28e1405285c99a903f16b16bf39428ca3db6caea 100644
--- a/src/builtins/builtins-sharedarraybuffer.cc
+++ b/src/builtins/builtins-sharedarraybuffer.cc
@@ -249,8 +249,8 @@ void Builtins::Generate_AtomicsStore(CodeStubAssembler* a) {
   a->Return(value_integer);
 
   a->Bind(&u16);
-  a->SmiTag(a->AtomicStore(MachineRepresentation::kWord16, backing_store,
-                           a->WordShl(index_word, 1), value_word32));
+  a->AtomicStore(MachineRepresentation::kWord16, backing_store,
+                 a->WordShl(index_word, 1), value_word32);
   a->Return(value_integer);
 
   a->Bind(&u32);