ada: Etype missing for raise expression

If the primitive equality operator of the component type of an array type is
abstract, then a call to that abstract function raises Program_Error (when
such a call is legal). The FE generates a raise expression to implement this.
That raise expression is an expression so it should have a valid Etype.

gcc/ada/

	* exp_ch4.adb (Build_Eq_Call): In the abstract callee case, copy
	the Etype of the callee onto the Make_Raise_Program_Error result.

gcc/ada/exp_ch4.adb

@@ -443,8 +443,11 @@ package body Exp_Ch4 is
    begin
       if Present (Eq) then
          if Is_Abstract_Subprogram (Eq) then
-            return Make_Raise_Program_Error (Loc,
-               Reason =>  PE_Explicit_Raise);
+            return Result : constant Node_Id :=
+              Make_Raise_Program_Error (Loc, Reason =>  PE_Explicit_Raise)
+            do
+               Set_Etype (Result, Etype (Eq));
+            end return;
          else
             return