Ensure CheckInitialized is present independent of define.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index cf01684729d9f4a433fbd1008d728752de6919a5..35ec462dc8a685393124d49e5a7d76348ab57d65 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -5397,11 +5397,12 @@ class Internals {
   static const int kUndefinedOddballKind = 5;
   static const int kNullOddballKind = 3;
 
+  static void CheckInitializedImpl(v8::Isolate* isolate);
+  V8_INLINE(static void CheckInitialized(v8::Isolate* isolate)) {
 #ifdef V8_ENABLE_CHECKS
-  static void CheckInitialized(v8::Isolate* isolate);
-#else
-  static void CheckInitialized(v8::Isolate* isolate) { }
+    CheckInitializedImpl(isolate);
 #endif
+  }
 
   V8_INLINE(static bool HasHeapObjectTag(internal::Object* value)) {
     return ((reinterpret_cast<intptr_t>(value) & kHeapObjectTagMask) ==