Overridable val should not be treated as constant

#KT-9443 fixed

compiler/testData/codegen/boxWithStdlib/evaluate/kt9443.kt

@@ -0,0 +1,18 @@
+abstract class BaseClass {
+    protected open val menuId: Int = 0
+
+    public fun run(): Pair<String, Boolean> =
+            "$menuId" to (menuId == 0)
+}
+
+class ImplClass: BaseClass() {
+    override val menuId: Int = 3
+}
+
+public fun box(): String {
+    val result = ImplClass().run()
+
+    if (result != ("3" to false)) return "Fail: $result"
+
+    return "OK"
+}

compiler/testData/evaluate/constant/classObjectProperty.kt

@@ -13,6 +13,12 @@ class A {
     // val prop4: 2
     val prop4 = A.a + 1
 
+    // val prop7: 0
+    open val prop7 = 0
+
+    // val prop8: null
+    val prop8 = prop7
+
     companion object {
         val a = 1
     }