meson: enable -fno-common by default

This flag is enabled by default starting with gcc 10.
All the compilation issues have been fixed, so use it by default
to make sure we're not introducing regressions.

Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4058>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4058>
1 file changed