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/callBy/extensionFunction.kt

@@ -0,0 +1,14 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// WITH_REFLECT
+
+import kotlin.test.assertEquals
+
+fun String.sum(other: String = "b") = this + other
+
+fun box(): String {
+    val f = String::sum
+    assertEquals("ab", f.callBy(mapOf(f.parameters.first() to "a")))
+    return "OK"
+}