Warn for keyword to last hash parameter when method has no optional/rest parameters
Warn for keyword to last hash parameter when method has no optional/rest parameters

Previously, there was no warning in this case, even though we will
be changing the behavior in Ruby 3.

Fixes [Bug #14130]

ruby/spec,nobu/rubyspec,eregon/rubyspec,eregon/rubyspec,ruby/spec,nobu/rubyspec,ruby/spec,nobu/rubyspec,eregon/rubyspec