arm: Fix the "c" constraint

The existing definition using register class CC_REG does not
work because CC_REGNUM does not support normal modes, and so
fails to match register_operand.  Use a non-register constraint
and the cc_register predicate instead.

        * config/arm/constraints.md (c): Use cc_register predicate.

From-SVN: r278224

gcc/ChangeLog

 2019-11-14  Richard Henderson  <richard.henderson@linaro.org>
 
+	* config/arm/constraints.md (c): Use cc_register predicate.
+
 	* config/aarch64/constraints.md (c): New constraint.
 
 2019-11-14  Jan Hubicka  <hubicka@ucw.cz>

gcc/config/arm/constraints.md

@@ -94,8 +94,9 @@
  "@internal
   Thumb only.  The union of the low registers and the stack register.")
 
-(define_register_constraint "c" "CC_REG"
- "@internal The condition code register.")
+(define_constraint "c"
+ "@internal The condition code register."
+ (match_operand 0 "cc_register"))
 
 (define_register_constraint "Cs" "CALLER_SAVE_REGS"
  "@internal The caller save registers.  Useful for sibcalls.")