mpi/fortran with -Wl,--as-needed

[Jeandet Alexis]

Hi,

I saw that -Wl,--as-needed would be enabled by default on Fedora 29, it
seems that we can't build a simple fortran program with this flag
either on Fedora 28 or 29 with openmpi at least.
Is this an MPI bug? Is this flag supposed to work in this context?
Any help here would be really welcome:
https://github.com/mesonbuild/meson/pull/4194

best regards,
Alexis.