gc.c: prototype
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44256 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
gc.c: prototype
instead of old K&R style.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44256 b2dd03c8-39d4-4d8f-98ff-823fe69b080e