Convert Fortran printing to value-based API

Convert Fortran printing to value-based API

This finishes the conversion of the Fortran printing code to the
value-based API.  The body of f_val_print is copied into
f_value_print_innner, and then modified as needed to use the value
API.

Note that not all calls must be updated.  For example, f77_print_array
remains "val-like", because it does not result in any calls to
val_print (f77_print_array_1 calls common_val_print, which is
nominally value-based).

gdb/ChangeLog
2020-03-13  Tom Tromey  <tom@tromey.com>

	* f-valprint.c (f_value_print_innner): Rewrite.