Revert of Introduce instance type for transition arrays.

src/transitions.cc

Index: src/transitions.cc
diff --git a/src/transitions.cc b/src/transitions.cc
index 4fe2ace3d94f28736bcef8e94db59e208fc3fee3..85e5dc7967dccc65235a6b6e274489498eed2e2e 100644
--- a/src/transitions.cc
+++ b/src/transitions.cc
@@ -391,23 +391,18 @@
 Handle<TransitionArray> TransitionArray::Allocate(Isolate* isolate,
                                                   int number_of_transitions,
                                                   int slack) {
-  Handle<FixedArray> array = isolate->factory()->NewTransitionArray(
-      LengthFor(number_of_transitions + slack));
-  array->set(kNextLinkIndex, isolate->heap()->undefined_value());
+  Handle<FixedArray> array = isolate->factory()->NewFixedArray(
+      LengthFor(number_of_transitions + slack), TENURED);
   array->set(kPrototypeTransitionsIndex, Smi::FromInt(0));
   array->set(kTransitionLengthIndex, Smi::FromInt(number_of_transitions));
   return Handle<TransitionArray>::cast(array);
 }
 
 
-// static
-void TransitionArray::ZapTransitionArray(TransitionArray* transitions) {
-  // Do not zap the next link that is used by GC.
-  STATIC_ASSERT(kNextLinkIndex + 1 == kPrototypeTransitionsIndex);
-  MemsetPointer(transitions->data_start() + kPrototypeTransitionsIndex,
+static void ZapTransitionArray(TransitionArray* transitions) {
+  MemsetPointer(transitions->data_start(),
                 transitions->GetHeap()->the_hole_value(),
-                transitions->length() - kPrototypeTransitionsIndex);
-  transitions->SetNumberOfTransitions(0);
+                transitions->length());
 }