[Bug #5153] [ruby-core:38736]

* io.c (argf_next_argv): remove the call of above function.

* ext/-test-/add_suffix, test/-ext-/test_add_suffix.rb: remove the test
  extension module because this is only for testsing ruby_add_suffix().

* LEGAL: remove the mention about a part of util.c, because now we
  removed the part.

* io.c (argf_next_argv): now the new filename is not guranteed to
  use, so should check the return value of rename(2).

* test/ruby/test_argf.rb (TestArgf#test_inplace_rename_impossible):
  now we expect same result with other platforms on no_safe_rename
  platforms (=Windows).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32826 b2dd03c8-39d4-4d8f-98ff-823fe69b080e