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/reflection/enclosing/objectInLambda.kt

@@ -0,0 +1,22 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// WITH_REFLECT
+
+fun box(): String {
+
+    val objectInLambda = {
+        object : Any () {}
+    }()
+
+    val enclosingMethod = objectInLambda.javaClass.getEnclosingMethod()
+    if (enclosingMethod?.getName() != "invoke") return "method: $enclosingMethod"
+
+    val enclosingClass = objectInLambda.javaClass.getEnclosingClass()!!.getName()
+    if (enclosingClass != "ObjectInLambdaKt\$box\$objectInLambda\$1") return "enclosing class: $enclosingClass"
+
+    val declaringClass = objectInLambda.javaClass.getDeclaringClass()
+    if (declaringClass != null) return "anonymous object has a declaring class"
+
+    return "OK"
+}