Properly close the CountOperation value/effect context after leaving the store effect context.

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7555 matching lines @@
       after = BuildIncrement(returns_original_input, expr);
 
       if (returns_original_input) {
         HValue* result = Pop();
         HValue* object = Pop();
         environment()->SetExpressionStackAt(0, result);
         {
           EffectContext for_effect(this);
           Push(object);
           Push(after);
-          return BuildStoreNamed(expr, expr->id(), expr->position(),
-                                 expr->AssignmentId(), prop, object, after);
+          BuildStoreNamed(expr, expr->id(), expr->position(),
+                          expr->AssignmentId(), prop, object, after);
         }
+        return ast_context()->ReturnValue(Pop());
       }
 
       return BuildStoreNamed(expr, expr->id(), expr->position(),
                              expr->AssignmentId(), prop, object, after);
     } else {
       // Keyed property.
       if (returns_original_input) Push(graph()->GetConstantUndefined());
 
       CHECK_ALIVE(VisitForValue(prop->obj()));
       CHECK_ALIVE(VisitForValue(prop->key()));
@@ skipping 2125 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal