IO#nonblock= and IO#close_on_exec= methods are simpler-to-use
and potentially more portable to for future OSes.
IO#nonblock= and IO#close_on_exec= are also smart enough to avoid
redundantly setting flags so a syscall may be avoided.
These methods could probably be removed entirely and inlined, but
it's unclear if there is 3rd-party code which relies on them.
* lib/webrick/utils.rb (set_non_blocking): use IO#nonblock=
* (set_close_on_exec): use IO#close_on_exec=
[Feature #11136]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50523 b2dd03c8-39d4-4d8f-98ff-823fe69b080e