[arm] clean up alu+shift patterns

[arm] clean up alu+shift patterns

My DImode arithmetic patches introduced a bug on thumb2 where we could
generate a register controlled shift into an ALU operation.  In
fairness the bug was always present, but latent.

As part of cleaning this up (and auditing to ensure I've caught them
all this time) I've gone through all the shift generating patterns in
the MD files and cleaned them up, reducing some duplicate patterns
between the arm and thumb2 descriptions where we can now share the
same pattern.  In some cases we were missing the shift attribute; in
most cases I've eliminated an ugly attribute setting using the fact
that we normally need separate alternatives for shift immediate and
shift reg to simplify the logic.

	* config/arm/iterators.md (t2_binop0): Fix typo in comment.
	* config/arm/arm.md (addsi3_carryin_shift): Simplify selection of the
	type attribute.
	(subsi3_carryin_shift): Separate into register and constant controlled
	alternatives.  Use shift_amount_operand for operand 4.  Set shift
	attribute and simplify type attribute.
	(subsi3_carryin_shift_alt): Likewise.
	(rsbsi3_carryin_shift): Likewise.
	(rsbsi3_carryin_shift_alt): Likewise.
	(andsi_not_shiftsi_si): Enable for TARGET_32BIT.  Separate constant
	and register controlled shifts into distinct alternatives.
	(andsi_not_shiftsi_si_scc_no_reuse): Likewise.
	(andsi_not_shiftsi_si_scc): Likewise.
	(arm_cmpsi_negshiftsi_si): Likewise.
	(not_shiftsi): Remove redundant M constraint from alternative 1.
	(not_shiftsi_compare0): Likewise.
	(arm_cmpsi_insn): Remove redundant alternative 2.
	(cmpsi_shift_swp): Likewise.
	(sub_shiftsi): Likewise.
	(sub_shiftsi_compare0_scratch): Likewise.
	* config/arm/thumb2.md (thumb_andsi_not_shiftsi_si): Delete pattern.
	(thumb2_cmpsi_neg_shiftsi): Likewise.

From-SVN: r277262