Use descriptors for reflection on class properties

- use ConcurrentHashMap as a cache of class loaders to module descriptors
- KClassImpl now has a lazy class descriptor and it manages property creation
  by looking (also lazily) for the property descriptor in the corresponding
  scope
- since deserialized descriptors have full information about where a JVM symbol
  is located and what signature it has, new tests will begin to pass where
  Kotlin model and Java reflection model differ, see classObjectVar.kt

compiler/testData/codegen/boxWithStdlib/callableReference/property/classObjectVar.kt

@@ -0,0 +1,15 @@
+class A {
+    default object B {
+        var state: String = "12345"
+    }
+}
+
+fun box(): String {
+    val p = A.B::state
+
+    if (p.name != "state") return "Fail state: ${p.name}"
+    if (p.get(A.B) != "12345") return "Fail value: ${p.get(A.B)}"
+    p.set(A.B, "OK")
+
+    return p[A.B]
+}