Add some tests on adapted references with varargs and reflection

Also rename "varargAndDefaults" test directory to "adaptedReferences"

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

@@ -0,0 +1,9 @@
+// KT-25514 Support usage of function reference with vararg where function of array is expected in new inference
+
+fun foo(x: Int, vararg y: String): String = y[0]
+
+fun useArray(f: (Int, Array<String>) -> String): String = f(1, Array(1) { "OK" })
+
+fun box(): String {
+    return useArray(::foo)
+}