FindMPI: Fortran include and module directories re-ordered incorrectly
Code added in !893 (merged) to FindMPI splits MPI_Fortran_F77_HEADER_DIR and MPI_Fortran_MODULE_DIR out from the include directories reported by mpif90 -showme:compile
and then re-assembles them into MPI_Fortran_INCLUDE_DIRS but does not preserve the order.
This leads to breakage like that reported on discourse where the gfortran
-specific module directory is generated after the Intel-specific module directory with Intel MPI, thus giving the compiler the wrong mpi.mod
file.