Duplicate symbols in C/Fortran MPICH libraries

[hansec]

Similar to #6814, I am building MPICH 4.2.3. statically (with -fPIC) on macOS. I find that both libraries libmpi.a/libpmpi.a and libmpifort.a contain the objects for the F08<->C status conversion functions (MPI_Status_c2f08, MPI_Status_f08c, PMPI_Status_c2f08, PMPI_Status_f08c). I later try to link all three libraries into a shared library, which fails because of duplicate symbols. This process works on 4.2.2.

The objects are defined in mpi_f08_types.o in libmpifort.a and in lib_libpmpi_la-c_binding.o/lib_libmpi_la-c_binding.o in libpmpi.a/libmpi.a.

I assume a fix similar to #6815 can fix this?