Support placement new syntax for zone objects and start using it in the parser.

src/zone-inl.h

Index: src/zone-inl.h
diff --git a/src/zone-inl.h b/src/zone-inl.h
index 516fc4aac5896e86a9e7e728e4800fe66ec4162d..17e83dc5ff496c9f79d9a82bb5fca9d36a7d7f22 100644
--- a/src/zone-inl.h
+++ b/src/zone-inl.h
@@ -97,6 +97,10 @@ void* ZoneObject::operator new(size_t size) {
   return ZONE->New(static_cast<int>(size));
 }
 
+void* ZoneObject::operator new(size_t size, Zone* zone) {
+  return zone->New(static_cast<int>(size));
+}
+
 
 inline void* ZoneListAllocationPolicy::New(int size) {
   return ZONE->New(size);