Double unboxing tests fixed.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/715263002

Cr-Commit-Position: refs/heads/master@{#25286}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25286 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/test-unboxed-doubles.cc

@@ -509,7 +509,8 @@ static Handle<LayoutDescriptor> TestLayoutDescriptorAppendIfFastOrUseFull(
     DCHECK(map->layout_descriptor()->IsConsistentWithMap(*map));
   }
 
-  Handle<LayoutDescriptor> layout_descriptor = map->GetLayoutDescriptor();
+  Handle<LayoutDescriptor> layout_descriptor(map->GetLayoutDescriptor(),
+                                             isolate);
   DCHECK(layout_descriptor->IsConsistentWithMap(*map));
   return layout_descriptor;
 }