Revert of [compiler] Properly guard the speculative optimizations for instanceof.

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index 00b667376a8247460526087fec984c12156e0349..e6c913486ae24361859b3f1e5322fcfaefcb94a4 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -11416,23 +11416,15 @@
               function->native_context()->closure() &&
           !function->map()->has_non_instance_prototype() &&
           isolate()->IsHasInstanceLookupChainIntact()) {
-        // Make sure the feedback for the instanceof is still fast (i.e. the
-        // vector slot is still unintialized).
-        Handle<TypeFeedbackVector> vector(current_feedback_vector(), isolate());
-        Handle<Object> feedback(
-            vector->Get(expr->CompareOperationFeedbackSlot()), isolate());
-        if (feedback.is_identical_to(
-                TypeFeedbackVector::UninitializedSentinel(isolate()))) {
-          Handle<Map> initial_map(function->initial_map(), isolate());
-          top_info()->dependencies()->AssumeInitialMapCantChange(initial_map);
-          top_info()->dependencies()->AssumePropertyCell(
-              isolate()->factory()->has_instance_protector());
-          HInstruction* prototype =
-              Add<HConstant>(handle(initial_map->prototype(), isolate()));
-          HHasInPrototypeChainAndBranch* result =
-              New<HHasInPrototypeChainAndBranch>(left, prototype);
-          return ast_context()->ReturnControl(result, expr->id());
-        }
+        Handle<Map> initial_map(function->initial_map(), isolate());
+        top_info()->dependencies()->AssumeInitialMapCantChange(initial_map);
+        top_info()->dependencies()->AssumePropertyCell(
+            isolate()->factory()->has_instance_protector());
+        HInstruction* prototype =
+            Add<HConstant>(handle(initial_map->prototype(), isolate()));
+        HHasInPrototypeChainAndBranch* result =
+            New<HHasInPrototypeChainAndBranch>(left, prototype);
+        return ast_context()->ReturnControl(result, expr->id());
       }
     }