ada: Cleanup more "not Present"

We had a GNATcheck rule that suggests replacing "not Present (...)" with
"No (...)", but it only detected calls with a parameter of type Node_Id.
Now this rules also detects parameters of type Elist_Id.

gcc/ada/

	* sem_ch3.adb, sem_ch4.adb, sem_eval.adb: Fix newly detected
	violations.