Revert 9111036: Promote double arrays to FAST_ELEMENT that use generic KeyedLoadIC

src/ic.cc

Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index 715c805ce068284fc9b382905fb1b0bb39e48b8b..b084109a713aa572bb79acdfb7f1155d8a9ba9f8 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -1120,17 +1120,6 @@ MaybeObject* KeyedLoadIC::Load(State state,
         } else if (key->IsSmi() && (target() != *non_strict_arguments_stub())) {
           stub = ComputeStub(receiver, LOAD, kNonStrictMode, stub);
         }
-        // If the IC is being replaced by the generic stub, loads from
-        // FAST_DOUBLE_ELEMENTS arrays will cause unboxing in Crankshafted
-        // code. To prevent these expensive allocations, proactively promote
-        // arrays to FAST_ELEMENTS ElementKinds.
-        if (*stub == *generic_stub()) {
-          if (receiver->HasFastDoubleElements()) {
-            MaybeObject* maybe_object =
-                receiver->TransitionElementsKind(FAST_ELEMENTS);
-            if (maybe_object->IsFailure()) return maybe_object;
-          }
-        }
       }
     } else {
       TRACE_GENERIC_IC("KeyedLoadIC", "force generic");