[Tests] Migrate backend-independent tests from native to compiler/testData.

^KT-65979

compiler/testData/codegen/box/basics/cast_simple.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+// WITH_STDLIB
+import kotlin.test.*
+
+open class A() {}
+class B(): A() {}
+
+fun castSimple(o: Any) : A = o as A
+
+fun castTest(): Boolean {
+  val b = B()
+  castSimple(b)
+  return true
+}
+
+fun box(): String {
+  if (!castTest()) throw Error()
+
+  return "OK"
+}