cris: Introduce CC_NZVCmode and CC_NZmode.

cris: Introduce CC_NZVCmode and CC_NZmode.

This is just the framework bits of splitting CCmode into classes
where the cc-setter can merge mode (CCmode), classes where the
cc-setter must set V and C "usefully" (as well as N and Z flags)
and classes where the cc-setter is something like an arithmetic
instruction, where N and Z are valid but C and V reflect the
operation rather than a compare of the result with zero.  This
should yield identical or near-identical code.

The old split of conditions into the ncond and ocond sets took
into account the transformations done by final.c:alter_cond from
cc_status.flags & CC_NO_OVERFLOW, and wasn't a reflection of the
hardware description of the conditions (i.e. whether V mattered
or not).

gcc:
	Prepare for cmpelim pass to eliminate redundant compare insns.
	* config/cris/cris-modes.def: New file.
	* config/cris/cris-protos.h (cris_select_cc_mode): Declare.
	(cris_notice_update_cc): Remove left-over declaration.
	* config/cris/cris.c (TARGET_CC_MODES_COMPATIBLE): Define.
	(cris_select_cc_mode, cris_cc_modes_compatible): New functions.
	* config/cris/cris.h (SELECT_CC_MODE): Define.
	* config/cris/cris.md (NZSET, NZUSE, NZVCSET, NZVCUSE): New
	mode_iterators.
	(cond): New code_iterator.
	(nzcond): Replacement for incorrect ncond.  All callers changed.
	(nzvccond): Replacement for ocond.  All callers changed.
	(rnzcond): Replacement for rcond.  All callers changed.
	(xCC): New code_attr.
	(cmp_op1c, cmp_op0c): Renumber from cmp_op1c and cmp_op2c.  All
	users changed.
	("*cmpdi<NZVCSET:mode>"): Rename from "*cmpdi".  Replace
	CCmode with iteration over NZVCSET.
	("*cmp_ext<BW:mode><NZVCSET:mode>"): Similarly; rename from
	"*cmp_ext<mode>".
	("*cmpsi<NZVCSET:mode>"): Similarly, from "*cmpsi".
	("*cmp<BW:mode><NZVCSET:mode>"): Similarly from "*cmp<mode>".
	("*btst<mode>"): Similarly, from "*btst".
	("*cbranch<mode><code>4"): Rename from "*cbranch<mode>4",
	iterating over cond instead of matching the comparison with
	ordered_comparison_operator.
	("*cbranch<mode>4_btstq<CC>"): Correct label operand number.
	("b<zcond:code><mode>"): Rename from "b<ncond:code>", iterating
	over NZUSE.
	("b<nzvccond:code><mode>"): Similarly from "b<ocond:code>", over
	NZVCUSE.  Remove FIXME.
	("*b<nzcond:code>_reversed<mode>"): Similarly from
	"*b<ncond:code>_reversed", over NZUSE.
	("*b<nzvccond:code>_reversed<mode>"): Similarly from
	"*b<ocond:code>_reversed", over NZVCUSE.  Remove FIXME.
	("b<rnzcond:code><mode>"): Similarly from "b<rcond:code>",
	over NZUSE.  Reinstate "b<oCC>" vs. "b<CC>" mnemonic choice,
	depending on CC_NZmode vs. CCmode.  Remove FIXME.
	("*b<rnzcond:code>_reversed<mode>"): Similarly from
	"*b<rcond:code>_reversed", over NZUSE.
	("*cstore<mode><code>4"): Rename from "*cstore<mode>4",
	iterating over cond instead of matching the comparison with
	ordered_comparison_operator.
	("*s<nzcond:code><mode>"): Rename from "*s<ncond:code>",
	iterating over NZUSE.
	("*s<rnzcond:code><mode>"): Similar from "*s<rcond:code>", over
	NZUSE.  Reinstate "b<oCC>" vs. "b<CC>" mnemonic choice,
	depending on CC_NZmode vs. CCmode.
	("*s<nzvccond:code><mode>"): Simlar from "*s<ocond:code>", over
	NZVCUSE.  Remove FIXME.