Free up 11 bits in fast-mode PropertyDetails by removing the enumeration-index.

test/cctest/test-alloc.cc

Index: test/cctest/test-alloc.cc
diff --git a/test/cctest/test-alloc.cc b/test/cctest/test-alloc.cc
index c20a08d3ed9c9c3314b88db32c5551faaf2a20fe..bc469aa5201f9e08d2163f1e3c03967180bb63d8 100644
--- a/test/cctest/test-alloc.cc
+++ b/test/cctest/test-alloc.cc
@@ -142,8 +142,7 @@ TEST(StressJS) {
 
   CallbacksDescriptor d(*name,
                         *foreign,
-                        static_cast<PropertyAttributes>(0),
-                        v8::internal::PropertyDetails::kInitialIndex);
+                        static_cast<PropertyAttributes>(0));
   map->AppendDescriptor(&d, witness);
 
   // Add the Foo constructor the global object.