(current_file_function_operand): New function, replaces
current_function_operand.
(print_operand, case 'F'): Case deleted.
(alpha_builtin_saveregs): Reworked to use homed arglists, as recommended in
the calling standard.
(alpha_need_gp): Deleted, code moved into output_prolog.
(alpha_gp_dead_after): Deleted; optimization is not safe.
(alpha_write_verstamp): New function.
(output_prolog, output_epilog): Major rework to update to current
calling standard.

From-SVN: r3459