Tweaks to print_rtx_function

Tweaks to print_rtx_function

gcc/ChangeLog:
	* print-rtl-function.c (print_edge): Omit "(flags)" when none are
	set.
	(print_rtx_function): Update example in comment for...
	* print-rtl.c (print_rtx_operand_code_r): In compact mode, print
	non-virtual pseudos with a '%' sigil followed by the regno, offset
	by (LAST_VIRTUAL_REGISTER + 1), so that the first non-virtual
	pseudo is dumped as "%0".

From-SVN: r241185