cris: update recent patterns. Simplify cris_select_cc_mode.

cris: update recent patterns. Simplify cris_select_cc_mode.

The code in cris_select_cc_mode for selecting CC_NZmode was
partly inconsistent with the comment and partly seemed
ambiguous.  I couldn't find a reason why I qualified selection
of CC_NZmode on the setting operation once a matching user was
spotted, so I just removed that.  The cris.c update was due to
observing the new test-case failing; the CC_NZmode compare
wasn't eliminated.

The recently re-instated adds/addu/subs/subu/bound patterns are
rewritten to replace the use of match_operator with iterators.

gcc:
	* config/cris/cris.c (cris_select_cc_mode): Always return
	CC_NZmode for matching comparisons.  Clarify comments.
	* config/cris/cris-modes.def: Clarify mode comment.
	* config/cris/cris.md (plusminus, plusminusumin, plusumin): New
	code iterators.
	(addsub, addsubbo, nd): New code iterator attributes.
	("*<addsub><su>qihi"): Rename from "*extopqihi".  Use code
	iterator constructs instead of match_operator constructs.
	("*<addsubbo><su><nd><mode>si<setnz>"): Similar from
	"*extop<mode>si<setnz>".
	("*add<su>qihi_swap"): Similar from "*addxqihi_swap".
	("*<addsubbo><su><nd><mode>si<setnz>_swap"): Similar from
	"*extop<mode>si<setnz>_swap".

gcc/testsuite:
	* gcc.target/cris/pr93372-39.c: New test.