Remove rb_hash_ar_table

It's dead code and duplicate of RHASH_AR_TABLE.

hash.c

@@ -579,13 +579,6 @@ rb_hash_ar_table_p(VALUE hash)
     }
 }
 
-ar_table *
-rb_hash_ar_table(VALUE hash)
-{
-    HASH_ASSERT(RHASH_AR_TABLE_P(hash));
-    return RHASH(hash)->as.ar;
-}
-
 st_table *
 rb_hash_st_table(VALUE hash)
 {

internal/hash.h

@@ -120,30 +120,6 @@ MJIT_SYMBOL_EXPORT_END
 
 VALUE rb_hash_compare_by_id(VALUE hash);
 
-#if 0 /* for debug */
-
-static inline bool
-RHASH_AR_TABLE_P(VALUE h)
-{
-    extern int rb_hash_ar_table_p(VALUE hash);
-    return rb_hash_ar_table_p(h)
-}
-
-static inline struct ar_table_struct *
-RHASH_AR_TABLE(VALUE h)
-{
-    extern struct ar_table_struct *rb_hash_ar_table(VALUE hash);
-    return rb_hash_ar_table(h)
-}
-
-static inline st_table *
-RHASH_ST_TABLE(VALUE h)
-{
-    return rb_hash_st_table(h)
-}
-
-#else
-
 static inline bool
 RHASH_AR_TABLE_P(VALUE h)
 {
@@ -162,8 +138,6 @@ RHASH_ST_TABLE(VALUE h)
     return RHASH(h)->as.st;
 }
 
-#endif
-
 static inline VALUE
 RHASH_IFNONE(VALUE h)
 {