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/properties/classFieldInsideNested.kt

@@ -0,0 +1,14 @@
+abstract class Your {
+    abstract val your: String
+
+    fun foo() = your
+}
+
+class My {
+    val my: String = "O"
+        get() = object : Your() {
+            override val your = field
+        }.foo() + "K"
+}
+
+fun box() = My().my