Provide "toString" for reflection objects

compiler/testData/codegen/boxWithStdlib/reflection/methodsFromAny/packageToString.kt

@@ -0,0 +1,10 @@
+package test.foo.bar
+
+import kotlin.test.*
+import kotlin.reflect.jvm.kotlinPackage
+
+fun box(): String {
+    val p = Class.forName("test.foo.bar.BarPackage").kotlinPackage
+    if ("$p" != "package test.foo.bar") return "Fail: $p"
+    return "OK"
+}