Pacify Win7 builders

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/22554002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16088 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/zone.h

@@ -249,6 +249,9 @@ class ZoneSplayTree: public SplayTree<Config, ZoneAllocationPolicy> {
   ~ZoneSplayTree();
 
   INLINE(void* operator new(size_t size, Zone* zone));
+
+  void operator delete(void* pointer) { UNREACHABLE(); }
+  void operator delete(void* pointer, Zone* zone) { UNREACHABLE(); }
 };