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/extensionFunctions/executionOrder.kt

@@ -0,0 +1,19 @@
+var result = ""
+
+fun getReceiver() : Int {
+    result += "getReceiver->"
+    return 1
+}
+
+fun getFun(b : Int.(Int)->Unit): Int.(Int)->Unit {
+    result += "getFun()->"
+    return b
+}
+
+fun box(): String {
+    getReceiver().(getFun({ result +="End" }))(1)
+
+    if(result != "getFun()->getReceiver->End") return "fail $result"
+
+    return "OK"
+}