Change spec to catch uninitialized argf
Change spec to catch uninitialized argf

* At some point a call would make all impls implicitly init.

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