Add some tests on adapted references with varargs and reflection

Also rename "varargAndDefaults" test directory to "adaptedReferences"

compiler/testData/codegen/box/callableReference/adaptedReferences/unboundReferences.kt

@@ -0,0 +1,49 @@
+// !LANGUAGE: +NewInference +FunctionReferenceWithDefaultValueAsOtherType
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+class C(val expected: Int) {
+    fun memberVararg(i: Int, vararg s: String) {
+        assertEquals(expected, i)
+        assertEquals(0, s.size)
+    }
+
+    fun memberDefault(i: Int, s: String = "") {
+        assertEquals(expected, i)
+        assertEquals("", s)
+    }
+
+    fun memberBoth(i: Int, s: String = "", vararg t: String) {
+        assertEquals(expected, i)
+        assertEquals("", s)
+        assertEquals(0, t.size)
+    }
+}
+
+fun C.extensionVararg(i: Int, vararg s: String) {
+    memberVararg(i, *s)
+}
+
+fun C.extensionDefault(i: Int, s: String = "") {
+    memberDefault(i, s)
+}
+
+fun C.extensionBoth(i: Int, s: String = "", vararg t: String) {
+    memberBoth(i, s, *t)
+}
+
+fun test(f: C.(Int) -> Unit, p: Int) = C(p).f(p)
+
+fun box(): String {
+
+    test(C::memberVararg, 43)
+    test(C::memberDefault, 43)
+    test(C::memberBoth, 43)
+    test(C::extensionVararg, 43)
+    test(C::extensionDefault, 43)
+    test(C::extensionBoth, 43)
+
+    return "OK"
+}