Revert "Kerenel#warn no longer splats an array in 2.5 (#382)" (#429)
Revert "Kerenel#warn no longer splats an array in 2.5 (#382)" (#429)

This reverts commit 859eeb08396d8520ca144727876d5490aeb50124.

https://bugs.ruby-lang.org/issues/12944#change-64454
nobu/rubyspec,ruby/spec,sgarciac/spec,ruby/rubyspec,sgarciac/spec,eregon/rubyspec,ruby/rubyspec,ruby/spec,ruby/spec,eregon/rubyspec,nobu/rubyspec,eregon/rubyspec,sgarciac/spec,nobu/rubyspec