[arm] fix constraints on addsi3_carryin_alt2

addsi3_carryin_alt2 has a more strict constraint than the predicate
when adding a constant.  This leads to sub-optimal code in some
circumstances.

	* config/arm/arm.md (addsi3_carryin_alt2): Use arm_not_operand for
	operand 2.

From-SVN: r277168

gcc/ChangeLog

 2019-10-18  Richard Earnshaw  <rearnsha@arm.com>
 
+	* config/arm/arm.md (addsi3_carryin_alt2): Use arm_not_operand for
+	operand 2.
+
+2019-10-18  Richard Earnshaw  <rearnsha@arm.com>
+
 	* config/arm/arm.md (addsi3_carryin_shift_<optab>): Reorder operands
 	to match canonical form.
 

gcc/config/arm/arm.md

@@ -893,7 +893,7 @@
   [(set (match_operand:SI 0 "s_register_operand" "=l,r,r")
         (plus:SI (plus:SI (LTUGEU:SI (reg:<cnb> CC_REGNUM) (const_int 0))
                           (match_operand:SI 1 "s_register_operand" "%l,r,r"))
-                 (match_operand:SI 2 "arm_rhs_operand" "l,rI,K")))]
+                 (match_operand:SI 2 "arm_not_operand" "l,rI,K")))]
   "TARGET_32BIT"
   "@
    adc%?\\t%0, %1, %2