Add support for enabling DCHECKs in release mode

src/ic/ic.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_IC_H_
 #define V8_IC_H_
 
 #include "src/ic/ic-state.h"
 #include "src/macro-assembler.h"
 
@@ skipping 70 matching lines @@
   static void RegisterWeakMapDependency(Handle<Code> stub);
 
   // This function is called when a weak map in the stub is dying,
   // invalidates the stub by setting maps in it to undefined.
   static void InvalidateMaps(Code* stub);
 
   // Clear the inline cache to initial state.
   static void Clear(Isolate* isolate, Address address,
                     ConstantPoolArray* constant_pool);
 
-#ifdef DEBUG
+#if DCHECK_IS_ON
   bool IsLoadStub() const {
     return target()->is_load_stub() || target()->is_keyed_load_stub();
   }
 
   bool IsStoreStub() const {
     return target()->is_store_stub() || target()->is_keyed_store_stub();
   }
 
   bool IsCallStub() const { return target()->is_call_stub(); }
 #endif
@@ skipping 659 matching lines @@
 
 // Support functions for interceptor handlers.
 DECLARE_RUNTIME_FUNCTION(LoadPropertyWithInterceptorOnly);
 DECLARE_RUNTIME_FUNCTION(LoadPropertyWithInterceptor);
 DECLARE_RUNTIME_FUNCTION(LoadElementWithInterceptor);
 DECLARE_RUNTIME_FUNCTION(StorePropertyWithInterceptor);
 }
 }  // namespace v8::internal
 
 #endif  // V8_IC_H_