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/methodsFromAny/memberExtensionToString.kt

@@ -0,0 +1,24 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// WITH_REFLECT
+
+import kotlin.reflect.*
+
+class A {
+    var String.id: String
+        get() = this
+        set(value) {}
+
+    fun Int.foo(): Double = toDouble()
+}
+
+fun box(): String {
+    val p = A::class.java.kotlin.memberExtensionProperties.single()
+    return if ("$p" == "var A.(kotlin.String.)id: kotlin.String") "OK" else "Fail $p"
+
+    val q = A::class.java.kotlin.declaredFunctions.single()
+    if ("$q" != "fun A.(kotlin.Int.)foo(): kotlin.Double") return "Fail q $q"
+
+    return "OK"
+}