All compile-time messages about division by zero are now located at the
right operand. Previously some of them were located at the division
operator, which was inconsistent.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* sem_eval.adb (Eval_Arithmetic_Op): Add Loc parameter to all
	calls to Apply_Compile_Time_Constraint_Error related to division
	by zero.