tests: check whether -Wl,--unresolved-symbols=ignore-all is supported

When linking for macOS, this linker flag is rejected. Instead of
always passing it, we can check whether it is supported first.

Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
Reviewed-by: Simon Ser <contact@emersion.fr>
4 jobs for main in 15 minutes and 4 seconds
Status Name Job ID Coverage
  Review
passed check-commit #14583702

00:05:13

 
  Containers Build
passed container_build #14583703

00:05:22

 
  Test
passed test-autotools #14583705

00:04:28

passed test-meson #14583704

00:04:25