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/functions/kt1199.kt

@@ -0,0 +1,30 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+
+interface MyIterator<T> {
+    operator fun hasNext() : Boolean
+    operator fun next() : T
+}
+
+operator fun <T : Any> T?.iterator() = object : MyIterator<T> {
+    var hasNext = this@iterator != null
+      private set
+    override fun hasNext() = hasNext
+
+    override fun next() : T {
+        if (hasNext) {
+            hasNext = false
+            return this@iterator!!
+        }
+        throw java.util.NoSuchElementException()
+    }
+}
+
+fun box() : String {
+  var k = 0
+  for (i in 1) {
+    k++
+  }
+  return if(k == 1) "OK" else "fail"
+}