Method#parameters doesn't annotate required parameters correctly #2918
Description
JRuby 9.0.0.0 incorrectly reports required parameters as "rest" in Method#parameters.
> ruby -v -e 'def m(x); end; p method(:m).parameters'
ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-linux]
[[:req, :x]]
> bin/jruby -v -e 'def m(x); end; p method(:m).parameters'
jruby 9.0.0.0-SNAPSHOT (2.2.2) 2015-05-08 c957028 Java HotSpot(TM) 64-Bit Server VM 25.45-b02 on 1.8.0_45-b14 +jit [linux-amd64]
[[:rest, :x]]