Track peak Zone memory usage and report it via HeapStatistics

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index fa827d41f575f4c54f5e758de28a961545b2e29a..c7766934c00c7b88e161c27fffe70cafb10171e9 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -5248,6 +5248,7 @@ class V8_EXPORT HeapStatistics {
   size_t used_heap_size() { return used_heap_size_; }
   size_t heap_size_limit() { return heap_size_limit_; }
   size_t malloced_memory() { return malloced_memory_; }
+  size_t peak_malloced_memory() { return peak_malloced_memory_; }
   size_t does_zap_garbage() { return does_zap_garbage_; }
 
  private:
@@ -5258,6 +5259,7 @@ class V8_EXPORT HeapStatistics {
   size_t used_heap_size_;
   size_t heap_size_limit_;
   size_t malloced_memory_;
+  size_t peak_malloced_memory_;
   bool does_zap_garbage_;
 
   friend class V8;