Support Kotlin annotation constructors in reflection

#KT-13106 In Progress

compiler/testData/codegen/box/reflection/constructors/annotationClass.kt

@@ -0,0 +1,21 @@
+// WITH_REFLECT
+
+import kotlin.reflect.*
+import kotlin.test.assertEquals
+
+annotation class A1
+
+annotation class A2(val k: KClass<*>, val s: A1)
+
+fun box(): String {
+    assertEquals(1, A1::class.constructors.size)
+    assertEquals(A1::class.primaryConstructor, A1::class.constructors.single())
+
+    val cs = A2::class.constructors
+    assertEquals(1, cs.size)
+    assertEquals(A2::class.primaryConstructor, cs.single())
+    val params = cs.single().parameters
+    assertEquals(listOf("k", "s"), params.map { it.name })
+
+    return "OK"
+}