test/ignore-single-mmap: add test case for ignoring FEAT_SINGLE_MMAP

Fixed by kernel commit:

https://git.kernel.dk/cgit/linux/commit/?h=io_uring-6.10&id=06fe9b1df1086b42718d632aa57e8f7cd1a66a21

and only existed in the 6.10-rc1 kernel. Explanation in test case itself.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2 files changed