patches/patch-lib_isc_unix_socket.c appears to have lost the definition of _XOPEN_SOURCE required for SmartOS.

Specifically I believe this might be the culprit: ce4a3bf#diff-1285c7d3bbb0e62c17003e1f8bccc791851efd65b4cf340c3f24f69bc6b8099a

The consequence can be found at:
http://mail-index.netbsd.org/pkgsrc-bulk/2022/02/14/msg022049.html
https://us-east.manta.joyent.com/pkgsrc/public/reports/upstream-trunk/20220213.2256/bind-9.16.25/build.log