Add Range#% to call-seq [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64873 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

range.c

@@ -350,10 +350,14 @@ range_step_size(VALUE range, VALUE args, VALUE eobj)
 }
 
 /*
+ *  Document-method: Range#step
+ *  Document-method: Range#%
  *  call-seq:
  *     rng.step(n=1) {| obj | block }    -> rng
  *     rng.step(n=1)                     -> an_enumerator
  *     rng.step(n=1)                     -> an_arithmetic_sequence
+ *     rng % n                           -> an_enumerator
+ *     rng % n                           -> an_arithmetic_sequence
  *
  *  Iterates over the range, passing each <code>n</code>th element to the block.
  *  If begin and end are numeric, +n+ is added for each iteration.