/usr/lib/x86_64-linux-gnu/pkgconfig/ is in libxen-dev 4.9.2-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/pkgconfig/xencall.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xencontrol.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xendevicemodel.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenevtchn.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenforeignmemory.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xengnttab.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenguest.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenlight.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenstat.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenstore.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xentoollog.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xenvchan.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/xlutil.pc