Add -optimize-for-size flag to optimize for memory size

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 79f4478ea6f626ff297314b4ed227d5dc088abed..73e91f49f9b3402ef6b78b4554e924f944f49d5b 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3745,20 +3745,12 @@ class V8_EXPORT ResourceConstraints {
   uint32_t* stack_limit() const { return stack_limit_; }
   // Sets an address beyond which the VM's stack may not grow.
   void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
-  Maybe<bool> is_memory_constrained() const { return is_memory_constrained_; }
-  // If set to true, V8 will limit it's memory usage, at the potential cost of
-  // lower performance.  Note, this option is a tentative addition to the API
-  // and may be removed or modified without warning.
-  void set_memory_constrained(bool value) {
-    is_memory_constrained_ = Maybe<bool>(value);
-  }
 
  private:
   int max_young_space_size_;
   int max_old_space_size_;
   int max_executable_size_;
   uint32_t* stack_limit_;
-  Maybe<bool> is_memory_constrained_;
 };