Add a spec for Hash#to_proc result passed as instance_exec block.
Add a spec for Hash#to_proc result passed as instance_exec block.

See jruby/jruby#4037.

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