Tenure descriptor arrays.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 1d84188f6b7aee7f834107f6ade2c44eb878d1df..0f66aa17af251b9ceb62b3651de50f30a6585f2d 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9823,7 +9823,7 @@ Handle<DescriptorArray> DescriptorArray::Allocate(Isolate* isolate,
   int size = number_of_descriptors + slack;
   if (size == 0) return factory->empty_descriptor_array();
   // Allocate the array of keys.
-  Handle<FixedArray> result = factory->NewFixedArray(LengthFor(size));
+  Handle<FixedArray> result = factory->NewFixedArray(LengthFor(size), TENURED);
 
   result->set(kDescriptorLengthIndex, Smi::FromInt(number_of_descriptors));
   result->set(kEnumCacheIndex, Smi::FromInt(0));