Convert function.length to API-style accessor.

src/accessors.h

Index: src/accessors.h
diff --git a/src/accessors.h b/src/accessors.h
index fc9ccf41a113c28e884b4fd1ca99ad5962e6ea18..226597a91062d383108932053693c7f3c39114b6 100644
--- a/src/accessors.h
+++ b/src/accessors.h
@@ -37,13 +37,13 @@ namespace internal {
 // The list of accessor descriptors. This is a second-order macro
 // taking a macro to be applied to all accessor descriptor names.
 #define ACCESSOR_DESCRIPTOR_LIST(V) \
-  V(FunctionLength)                 \
   V(FunctionName)                   \
   V(FunctionArguments)              \
   V(FunctionCaller)                 \
   V(ArrayLength)
 
 #define ACCESSOR_INFO_LIST(V)       \
+  V(FunctionLength)                 \
   V(FunctionPrototype)              \
   V(ScriptColumnOffset)             \
   V(ScriptCompilationType)          \