gdb/fortran: Implement la_print_typedef for Fortran
Implement an la_print_typedef method for Fortran, this allows 'info
types' to work for Fortran. The implementation is just copied from
ada_print_typedef (with the appropriate changes).
To support the testing of this patch I added a new proc,
fortran_character1, to lib/fortran.exp which returns a regexp to match
a 1-byte character type. The regexp returned is correct for current
versions of gFortran. All of the other regexp are guesses based on
all of the other support procs in lib/fortran.exp, I haven't tested
them myself.