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

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index ee6df1d2abd77561dfec632cfddc25efcf44a0be..664a8211560f28bc39d8e620e4e6c67c58f9425f 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -323,10 +323,6 @@ void Map::MapVerify() {
           instance_size() < HEAP->Capacity()));
   VerifyHeapPointer(prototype());
   VerifyHeapPointer(instance_descriptors());
-  DescriptorArray* descriptors = instance_descriptors();
-  for (int i = 0; i < NumberOfOwnDescriptors(); ++i) {
-    CHECK_EQ(i, descriptors->GetDetails(i).descriptor_index() - 1);
-  }
   SLOW_ASSERT(instance_descriptors()->IsSortedNoDuplicates());
   if (HasTransitionArray()) {
     SLOW_ASSERT(transitions()->IsSortedNoDuplicates());