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/closures/noRefToOuter.kt

@@ -0,0 +1,22 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// WITH_RUNTIME
+
+class A {
+    fun f(): () -> String {
+        val s = "OK"
+        return { -> s }
+    }
+}
+
+fun box(): String {
+    val lambdaClass = A().f().javaClass
+    val fields = lambdaClass.getDeclaredFields().toList()
+    if (fields.size != 1) return "Fail: lambda should only capture 's': $fields"
+
+    val fieldName = fields[0].getName()
+    if (fieldName != "\$s") return "Fail: captured variable should be named '\$s': $fields"
+
+    return "OK"
+}