ChangeLog: fix a typo [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48542 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
trivial packing of rb_execarg, load_file_arg, args_info

* internal.h (struct rb_execarg): 160 => 144 bytes on x86-64
* ruby.c (struct load_file_arg): 48 => 40 bytes on x86-64
* vm_args.c (struct args_info): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48543 b2dd03c8-39d4-4d8f-98ff-823fe69b080e