Make KeyedLoads from a sloppy arguments array use a handler.

src/elements-kind.h

Index: src/elements-kind.h
diff --git a/src/elements-kind.h b/src/elements-kind.h
index b48a5dfe024ddc1906d123d8fee7cd8d02b54464..fb973411eccb3f07a989d132b66bc7e4bed30678 100644
--- a/src/elements-kind.h
+++ b/src/elements-kind.h
@@ -87,6 +87,11 @@ inline bool IsDictionaryElementsKind(ElementsKind kind) {
 }
 
 
+inline bool IsSloppyArgumentsElements(ElementsKind kind) {
+  return kind == SLOPPY_ARGUMENTS_ELEMENTS;
+}
+
+
 inline bool IsExternalArrayElementsKind(ElementsKind kind) {
   return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND &&
       kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND;