/usr/include/linux/irqnr.h is in linux-libc-dev 4.15.0-20.21.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | /*
* There isn't anything here anymore, but the file must not be empty or patch
* will delete it.
*/
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