ada-valprint.c: Reorder functions to reduce advance declarations.

ada-valprint.c: Reorder functions to reduce advance declarations.

Advance function declarations add to the maintenance cost, since
any update to the function prototype needs to be made twice.
For static functions, this is not necessary, and this patch
reorders the function so as to reduce the use of such advanche
declarations.

gdb/ChangeLog:

        * ada-valprint.c (print_record): Delete declaration.
        (adjust_type_signedness, ada_val_print_1): Likewise.
        (ada_val_print): Move function implementation down.
        (print_variant_part, print_field_values, print_record):
        Move function implementation up.