Kotlin: Add a Kotlin 2 copy of the testsuite

java/ql/test-kotlin2/query-tests/UselessParameter/Test.kt

@@ -0,0 +1,24 @@
+interface A<T, V> {
+    fun setValue(a: T, b: V)
+}
+
+class B : A<B, Int> {
+    override fun setValue(a: B, b: Int) {
+        println("a")
+    }
+}
+
+fun fn(a: Int = 10) {}
+
+class C {
+    companion object {}
+}
+
+object O {}
+
+fun C.fn() {}
+fun C.Companion.fn() {}
+fun O.fn() {}
+
+@Suppress("UNUSED_PARAMETER")
+fun fn2(a: Int) {}

java/ql/test-kotlin2/query-tests/UselessParameter/UselessParameter.qlref

@@ -0,0 +1 @@
+DeadCode/UselessParameter.ql