Remove HCheckSmi, LCheckSmi and rename LCheckSmiAndReturn to LCheckSmi.

src/code-stubs-hydrogen.cc

Index: src/code-stubs-hydrogen.cc
diff --git a/src/code-stubs-hydrogen.cc b/src/code-stubs-hydrogen.cc
index 05af70401e9e3530dd68eea192b643c2eb7bc94c..4280fa43fcfb745fb7d6a91ddab843a4593acf3e 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -642,11 +642,6 @@ HValue* CodeStubGraphBuilder<ArrayNArgumentsConstructorStub>::BuildCodeStub() {
   HInstruction* argument = AddInstruction(new(zone()) HAccessArgumentsAt(
       argument_elements, length, key));
 
-  // Checks to prevent incompatible stores
-  if (IsFastSmiElementsKind(kind)) {
-    AddInstruction(new(zone()) HCheckSmi(argument));
-  }
-
   AddInstruction(new(zone()) HStoreKeyed(elements, key, argument, kind));
   builder.EndBody();
   return new_object;