Change nm so that when it is running in POSIX compatible mode, it does not prefix symbol values with 0.

	PR 24507
	* nm.c: (print_format): New variable.
	(value_format_32bit, value_format_64bit): Delete.
	(set_print_radix): Remove code to alter value_format strings.
	(set_output_format): Record chosen format in print_format.
	(get_print_format): New function - constructs a printf formatting
	string according to the requirements of size, radix, and output
	format.
	(print_value): Use get_print_format.
	* testsuite/binutils-all/nm.exp: Add tests of "nm --format=posix"
	and "nm -t d".