Assign specialized array functions only once.

src/runtime.h

Index: src/runtime.h
diff --git a/src/runtime.h b/src/runtime.h
index f9dc5990d3404a777c9a8ca8222606c28c69ede9..24256b0837f34f6306b2009ea35f23b6282800d1 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -61,6 +61,7 @@ namespace internal {
   F(ToFastProperties, 1, 1) \
   F(ToSlowProperties, 1, 1) \
   F(FinishArrayPrototypeSetup, 1, 1) \
+  F(SpecialArrayFunctions, 1, 1) \
   \
   F(IsInPrototypeChain, 2, 1) \
   F(SetHiddenPrototype, 2, 1) \