gspawn: Use CLOSE_RANGE_CLOEXEC if available
It’s a new flag added to close_range()
in kernel 5.11, which will
allow us to speed up setting CLOEXEC
on ranges of file descriptors.
This currently happens in some situations when executing a new binary
with GSpawn
.
Signed-off-by: Philip Withnall pwithnall@endlessos.org