Enable --verify-heap in release mode

src/heap-inl.h

Index: src/heap-inl.h
diff --git a/src/heap-inl.h b/src/heap-inl.h
index 13be88aab40866eb51eea1c02fa6bf7308e10aa8..52c67afc8200e654bd827d8e7493ac72f0ccdfcb 100644
--- a/src/heap-inl.h
+++ b/src/heap-inl.h
@@ -741,17 +741,15 @@ AlwaysAllocateScope::~AlwaysAllocateScope() {
 }
 
 
-#ifdef DEBUG
 void VerifyPointersVisitor::VisitPointers(Object** start, Object** end) {
   for (Object** current = start; current < end; current++) {
     if ((*current)->IsHeapObject()) {
       HeapObject* object = HeapObject::cast(*current);
-      ASSERT(HEAP->Contains(object));
-      ASSERT(object->map()->IsMap());
+      CHECK(HEAP->Contains(object));
+      CHECK(object->map()->IsMap());
     }
   }
 }
-#endif
 
 
 double GCTracer::SizeOfHeapObjects() {