Can you do me a favor and cd into ompi/mpi/fortran/use-mpi-f08 and try to manually "make type_create_indexed_block_f08.lo" and see if it also complains? That's a 32 character name -- let's see if the limit is >=32 or >=33...
Perhaps you came to the same conclusion already, but just in case:
I think the simplest approach to this problem is to include a configure check with the longest name in the interface (without regard to WHAT that length is). This would be added to the ever-growing list of probes of BIND behavior. If the compiler can't handle the longest name required, then it is disqualified from building use-mpi-f08.
Of course that solution adeptly avoids the "Internal" failure in PathScale and Open64 compilers, but a configure option to disable the F08 support addresses that and other misc cases of fortran compilers that just aren't ready for F08 (or 03 for that matter).