First implementation of allocation elimination in Hydrogen.

src/zone.h

Index: src/zone.h
diff --git a/src/zone.h b/src/zone.h
index a12ed79312333b896277a1ec2067f505d4055b3c..627d2b3502b7ef8cc2eedffd6e1a927498f36bba 100644
--- a/src/zone.h
+++ b/src/zone.h
@@ -201,7 +201,7 @@ class ZoneList: public List<T, ZoneAllocationPolicy> {
   ZoneList(const ZoneList<T>& other, Zone* zone)
       : List<T, ZoneAllocationPolicy>(other.length(),
                                       ZoneAllocationPolicy(zone)) {
-    AddAll(other, ZoneAllocationPolicy(zone));
+    AddAll(other, zone);
   }
 
   // We add some convenience wrappers so that we can pass in a Zone
@@ -209,8 +209,7 @@ class ZoneList: public List<T, ZoneAllocationPolicy> {
   INLINE(void Add(const T& element, Zone* zone)) {
     List<T, ZoneAllocationPolicy>::Add(element, ZoneAllocationPolicy(zone));
   }
-  INLINE(void AddAll(const List<T, ZoneAllocationPolicy>& other,
-                     Zone* zone)) {
+  INLINE(void AddAll(const List<T, ZoneAllocationPolicy>& other, Zone* zone)) {
     List<T, ZoneAllocationPolicy>::AddAll(other, ZoneAllocationPolicy(zone));
   }
   INLINE(void AddAll(const Vector<T>& other, Zone* zone)) {