sprintf.c: get_num

* sprintf.c (get_num): utility function for GETNUM().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46656 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
sprintf.c: check_next_arg

* sprintf.c (check_next_arg): utility function for GETNEXTARG().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
sprintf.c: check_pos_arg

* sprintf.c (check_pos_arg): utility function for GETPOSARG().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46658 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
sprintf.c: check_name_arg

* sprintf.c (check_name_arg): utility function for GETNAMEARG().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46659 b2dd03c8-39d4-4d8f-98ff-823fe69b080e