First, there's no reason not to use the new `epoll_create1` system call,
which quickly obsoleted `epoll_create` which has an obsolete and
unused size argument.
But more specifically, it offers `EPOLL_CLOEXEC` which we want
to use for general hygeine - there's no reason to potentially
leak this file descriptor to forked processes.
(GLib itself carefully closes file descriptors when forking child
processes, but it may be linked with other software that doesn't;
notably in my case for example the Rust standard library does not
do this and hence relies more on the application code using
`O_CLOEXEC` and variants)
This is just a drive-by fix; I saw the system call when I was using
`strace` to debug something else in rpm-ostree.
Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.
This commit was entirely generated using the command:
```
git ls-files gio/*.[ch] | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
