Fixed regexp zone issue

src/zone.h

Index: src/zone.h
diff --git a/src/zone.h b/src/zone.h
index 9721b0724b9324e6b9063753b58bb042d426bca3..612819e5425bc40b16f5666b62b019b9ce52b2c8 100644
--- a/src/zone.h
+++ b/src/zone.h
@@ -65,8 +65,9 @@ class Zone {
   // the limit allows.
   static inline bool excess_allocation();
 
+  static inline void adjust_segment_bytes_allocated(int delta);
+
  private:
-  friend class Segment;
 
   // All pointers returned from New() have this alignment.
   static const int kAlignment = kPointerSize;
@@ -183,6 +184,8 @@ class ZoneScope BASE_EMBEDDED {
     mode_ = DELETE_ON_EXIT;
   }
 
+  static int nesting() { return nesting_; }
+
  private:
   ZoneScopeMode mode_;
   static int nesting_;