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

^KT-65979

compiler/testData/codegen/box/function/defaults5.kt

@@ -0,0 +1,28 @@
+/*
+ * 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.
+ */
+// JVM_ABI_K1_K2_DIFF: KT-63864
+// WITH_STDLIB
+
+import kotlin.test.*
+
+val sb = StringBuilder()
+
+class TestClass(val x: Int) {
+    fun foo(y: Int = x) {
+        sb.appendLine(y)
+    }
+}
+
+fun TestClass.bar(y: Int = x) {
+    sb.appendLine(y)
+}
+
+fun box(): String {
+    TestClass(5).foo()
+    TestClass(6).bar()
+
+    assertEquals("5\n6\n", sb.toString())
+    return "OK"
+}