Now that RHEL/CentOS 5 is end-of-life, update the baseline from
linux >= 2.6.18 + glibc >= 2.5 to linux >= 2.6.32 + glibc >= 2.12.
PR-URL: https://github.com/libuv/libuv/pull/1324
Refs: https://github.com/nodejs/node/pull/12672
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>