[WIP] Proxy fix for for-in.

src/compiler/js-typed-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/linkage.h"
@@ skipping 2189 matching lines @@
     cache_type_true0 = cache_type;
   }
 
   Node* if_false0 = graph()->NewNode(common()->IfFalse(), branch0);
   Node* cache_array_false0;
   Node* cache_length_false0;
   Node* cache_type_false0;
   Node* efalse0;
   {
     // FixedArray case.
-    Node* receiver_instance_type = efalse0 = graph()->NewNode(
-        simplified()->LoadField(AccessBuilder::ForMapInstanceType()),
-        receiver_map, effect, if_false0);
-
-    cache_type_false0 = graph()->NewNode(
-        common()->Select(MachineRepresentation::kTagged, BranchHint::kFalse),
-        graph()->NewNode(machine()->Word32Equal(), receiver_instance_type,
-                         jsgraph()->Uint32Constant(JS_PROXY_TYPE)),
-        jsgraph()->ZeroConstant(),  // Zero indicagtes proxy.
-        jsgraph()->OneConstant());  // One means slow check.
-
+    cache_type_false0 = jsgraph()->ZeroConstant();  // Smi means slow check
     cache_array_false0 = cache_type;
     cache_length_false0 = efalse0 = graph()->NewNode(
         simplified()->LoadField(AccessBuilder::ForFixedArrayLength()),
-        cache_array_false0, efalse0, if_false0);
+        cache_array_false0, effect, if_false0);
   }
 
   control = graph()->NewNode(common()->Merge(2), if_true0, if_false0);
   effect = graph()->NewNode(common()->EffectPhi(2), etrue0, efalse0, control);
   Node* cache_array =
       graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                        cache_array_true0, cache_array_false0, control);
   Node* cache_length =
       graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, 2),
                        cache_length_true0, cache_length_false0, control);
@@ skipping 438 matching lines @@
 }
 
 
 CompilationDependencies* JSTypedLowering::dependencies() const {
   return dependencies_;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8