Introduce KAnnotatedElement and val annotations: List<Annotation>

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

@@ -0,0 +1,7 @@
+annotation(retention = AnnotationRetention.RUNTIME) class Simple(val value: String)
+
+fun test(@Simple("OK") x: Int) {}
+
+fun box(): String {
+    return (::test.parameters.single().annotations.single() as Simple).value
+}