Classes: Add support for toString

src/heap/heap.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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 
 #include "src/allocation.h"
@@ skipping 322 matching lines @@
   V(megamorphic_symbol)             \
   V(premonomorphic_symbol)          \
   V(generic_symbol)                 \
   V(stack_trace_symbol)             \
   V(detailed_stack_trace_symbol)    \
   V(normal_ic_symbol)               \
   V(home_object_symbol)             \
   V(intl_initialized_marker_symbol) \
   V(intl_impl_object_symbol)        \
   V(promise_debug_marker_symbol)    \
-  V(promise_has_handler_symbol)
+  V(promise_has_handler_symbol)     \
+  V(class_script_symbol)            \
+  V(class_start_position_symbol)    \
+  V(class_end_position_symbol)
 
 // Forward declarations.
 class HeapStats;
 class Isolate;
 class WeakObjectRetainer;
 
 
 typedef String* (*ExternalStringTableUpdaterCallback)(Heap* heap,
                                                       Object** pointer);
 
@@ skipping 2153 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_