Tenure long-living descriptor arrays.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 8eb62ee7d92fb1d173d005f35b857388f627b03e..c17f56001d0dba271b6bbaf9f0c6dfa49734c628 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2983,9 +2983,9 @@ class DescriptorArray: public FixedArray {
 
   // Allocates a DescriptorArray, but returns the singleton
   // empty descriptor array object if number_of_descriptors is 0.
-  static Handle<DescriptorArray> Allocate(Isolate* isolate,
-                                          int number_of_descriptors,
-                                          int slack = 0);
+  static Handle<DescriptorArray> Allocate(
+      Isolate* isolate, int number_of_descriptors, int slack,
+      PretenureFlag pretenure = NOT_TENURED);
 
   DECLARE_CAST(DescriptorArray)