Add support for enabling DCHECKs in release mode

src/contexts.cc

 // Copyright 2011 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/v8.h"
 
 #include "src/bootstrapper.h"
 #include "src/debug.h"
 #include "src/scopeinfo.h"
 
@@ skipping 454 matching lines @@
 
 Handle<Object> Context::ErrorMessageForCodeGenerationFromStrings() {
   Isolate* isolate = GetIsolate();
   Handle<Object> result(error_message_for_code_gen_from_strings(), isolate);
   if (!result->IsUndefined()) return result;
   return isolate->factory()->NewStringFromStaticChars(
       "Code generation from strings disallowed for this context");
 }
 
 
-#ifdef DEBUG
+#if DCHECK_IS_ON
 bool Context::IsBootstrappingOrValidParentContext(
     Object* object, Context* child) {
   // During bootstrapping we allow all objects to pass as
   // contexts. This is necessary to fix circular dependencies.
   if (child->GetIsolate()->bootstrapper()->IsActive()) return true;
   if (!object->IsContext()) return false;
   Context* context = Context::cast(object);
   return context->IsNativeContext() || context->IsScriptContext() ||
          context->IsModuleContext() || !child->IsModuleContext();
 }
 
 
 bool Context::IsBootstrappingOrGlobalObject(Isolate* isolate, Object* object) {
   // During bootstrapping we allow all objects to pass as global
   // objects. This is necessary to fix circular dependencies.
   return isolate->heap()->gc_state() != Heap::NOT_IN_GC ||
       isolate->bootstrapper()->IsActive() ||
       object->IsGlobalObject();
 }
 #endif
 
 } }  // namespace v8::internal