backend/tests: Add blackbox tests from Kotlin JVM

Added tests from testData/codegen/box directory. There are blackbox tests
in other directories and they are to be added.

backend.native/tests/external/codegen/blackbox/delegatedProperty/delegateForExtPropertyInClass.kt

@@ -0,0 +1,20 @@
+import kotlin.reflect.KProperty
+
+class Delegate {
+    operator fun getValue(t: F.A, p: KProperty<*>): Int = 1
+}
+
+class F {
+    val A.prop: Int by Delegate()
+
+    class A {
+    }
+    
+    fun foo(): Int {
+       return A().prop 
+    }
+}
+
+fun box(): String {
+    return if(F().foo() == 1) "OK" else "fail"
+}