Annotations on type aliases: typealias is not a "default target".

Add diagnostic test for annotations on type aliases.

core/descriptors/src/org/jetbrains/kotlin/descriptors/annotations/KotlinTarget.kt

@@ -38,7 +38,7 @@ enum class KotlinTarget(val description: String, val isDefault: Boolean = true)
     TYPE("type usage", false),
     EXPRESSION("expression", false),           // includes FUNCTION_LITERAL, OBJECT_LITERAL
     FILE("file", false),
-    TYPEALIAS("typealias"),                    // TODO support typealias as annotation target
+    TYPEALIAS("typealias", false),
 
     TYPE_PROJECTION("type projection", false),
     STAR_PROJECTION("star projection", false),