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

^KT-65979

compiler/testData/codegen/box/boxing/boxing11.kt

@@ -0,0 +1,26 @@
+/*
+ * 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()
+
+fun printInt(x: Int) = sb.appendLine(x)
+
+class Foo(val value: Int?) {
+    fun foo() {
+        printInt(if (value != null) value else 42)
+    }
+}
+
+fun box(): String {
+    Foo(17).foo()
+    Foo(null).foo()
+
+    assertEquals("17\n42\n", sb.toString())
+    return "OK"
+}