Part of https://github.com/servo/servo/issues/34866
Implement signal abort, and part of running abort steps.
Signed-off-by: gterzian <2792687+gterzian@users.noreply.github.com>
This is a stub for `AbortSignal`, which we would like to merge first in
order to work in parallel on
https://github.com/servo/servo/issues/34866, and perhaps also
https://github.com/servo/servo/issues/36936
---------
Signed-off-by: gterzian <2792687+gterzian@users.noreply.github.com>
Signed-off-by: Taym Haddadi <haddadi.taym@gmail.com>
Co-authored-by: Taym Haddadi <haddadi.taym@gmail.com>
