Introduce KAnnotatedElement and val annotations: List<Annotation>

compiler/testData/codegen/boxWithStdlib/reflection/annotations/simpleConstructorAnnotation.kt

@@ -0,0 +1,13 @@
+annotation class Primary
+annotation class Secondary
+
+class C @Primary constructor() {
+    @Secondary
+    constructor(s: String): this()
+}
+
+fun box(): String {
+    val ans = C::class.constructors.map { it.annotations.single().annotationType().simpleName }.toSortedList()
+    if (ans != listOf("Primary", "Secondary")) return "Fail: $ans"
+    return "OK"
+}