* hash.c (recursive_hash): use RHASH_SIZE() to check hash size.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41928 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* hash.c (rb_hash_reject_bang): do not call rb_hash_foreach() if RHash
  has ntbl and it is empty.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41929 b2dd03c8-39d4-4d8f-98ff-823fe69b080e