[Ada] Remove redundant guard in expansion of dispatching calls

Routine Predefined_Primitive_Bodies, which create predefined primitives for derived tagged types, is only called with non-interface types entities (which is even enforced with an assertion at the very start of its body). There is no need to recheck this condition when creating individual primitive

[Ada] Remove redundant guard in expansion of dispatching calls

Routines Make_Predefined_Primitive_Specs and Predefined_Primitive_Bodies, which create predefined primitives for derived tagged types, are only called when restriction No_Dispatching_Calls is inactive. There is no need to recheck this restriction when creating individual primitive operations relate