first step to remove unsafe handles

src/api.h

Index: src/api.h
diff --git a/src/api.h b/src/api.h
index a9563469fd1899cd86e2e70b4eb2b84b8f26f510..b9ffbf56c8b0a7131f1745b4a59427428780e315 100644
--- a/src/api.h
+++ b/src/api.h
@@ -291,12 +291,21 @@ v8::internal::Handle<T> v8::internal::Handle<T>::EscapeFrom(
 }
 
 
+class InternalHandleHelper {
+ public:
+  template<class From, class To>
+  static inline Local<To> Convert(v8::internal::Handle<From> obj) {
+    return Local<To>(reinterpret_cast<To*>(obj.location()));
+  }
+};
+
+
 // Implementations of ToLocal
 
 #define MAKE_TO_LOCAL(Name, From, To)                                       \
   Local<v8::To> Utils::Name(v8::internal::Handle<v8::internal::From> obj) { \
     ASSERT(obj.is_null() || !obj->IsTheHole());                             \
-    return Local<To>(reinterpret_cast<To*>(obj.location()));                \
+    return InternalHandleHelper::Convert<v8::internal::From, v8::To>(obj);  \
   }
 
 
@@ -305,8 +314,8 @@ v8::internal::Handle<T> v8::internal::Handle<T>::EscapeFrom(
       v8::internal::Handle<v8::internal::JSTypedArray> obj) {               \
     ASSERT(obj.is_null() || !obj->IsTheHole());                             \
     ASSERT(obj->type() == typeConst);                                       \
-    return Local<v8::TypedArray>(                                           \
-        reinterpret_cast<v8::TypedArray*>(obj.location()));                 \
+    return InternalHandleHelper::                                           \
+        Convert<v8::internal::JSTypedArray, v8::TypedArray>(obj);           \
   }