[ruby/io-wait] Remove C99-ism for some platforms [ci skip]
Fix https://github.com/ruby/io-wait/pull/11
https://github.com/ruby/io-wait/commit/845f9a1f55
[ruby/io-wait] Remove C99-ism for some platforms [ci skip]
Fix https://github.com/ruby/io-wait/pull/11
https://github.com/ruby/io-wait/commit/845f9a1f55