Quieten errors relating to generic type aliases

Turns out type aliases are always substituted by the compiler, with the `IrSimpleType.abbreviation` field indicating what the original alias was if any. Therefore we're already extracting the right types. This commit simply omits extracting a kt_type for a type alias that uses type parameters as this certainly won't work at present because we don't have IrTypes for the type parameters declared by the alias and used in its RHS.

java/ql/test/kotlin/library-tests/type_aliases/aliases_with_type_parameters.kt

@@ -0,0 +1,7 @@
+class Test<T> {}
+
+typealias Alias2<R> = Test<R>
+
+typealias Alias1<S> = Alias2<S>
+
+fun f() : Alias1<String> = Test<String>()