Emit write barrier for old space constants.

src/crankshaft/hydrogen-instructions.h

 // Copyright 2012 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.
 
 #ifndef V8_CRANKSHAFT_HYDROGEN_INSTRUCTIONS_H_
 #define V8_CRANKSHAFT_HYDROGEN_INSTRUCTIONS_H_
 
 #include <cstring>
 #include <iosfwd>
 
@@ skipping 5480 matching lines @@
     // Stores to external references require no write barriers
     return false;
   }
   // We definitely need a write barrier unless the object is the allocation
   // dominator.
   if (object == dominator && object->IsAllocate()) {
     // Stores to new space allocations require no write barriers.
     if (HAllocate::cast(object)->IsNewSpaceAllocation()) {
       return false;
     }
-    // Stores to old space allocations require no write barriers if the value is
-    // a constant provably not in new space.
-    if (value->IsConstant() && HConstant::cast(value)->NotInNewSpace()) {
-      return false;
-    }
   }
   return true;
 }
 
 
 inline PointersToHereCheck PointersToHereCheckForObject(HValue* object,
                                                         HValue* dominator) {
   while (object->IsInnerAllocatedObject()) {
     object = HInnerAllocatedObject::cast(object)->base_object();
   }
@@ skipping 2049 matching lines @@
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CRANKSHAFT_HYDROGEN_INSTRUCTIONS_H_