The libirs contained own re-implementations of the getaddrinfo,
getnameinfo and gai_strerror + irs_context and irs_dnsconf API that was
unused anywhere in the BIND 9.
Keep just the irs_resonf API that is being extensively used to parse
/etc/resolv.conf by several of BIND 9 tools.
3760. [bug] Improve SIT with native PKCS#11 and on Windows.
[RT #35433]
3759. [port] Enable delve on Windows. [RT #35441]
3758. [port] Enable export library APIs on windows. [RT #35382]