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

^KT-65979

compiler/testData/codegen/box/inlineClass/customEquals.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2010-2020 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.
+ */
+// DONT_TARGET_EXACT_BACKEND: JVM
+// WITH_STDLIB
+@file:Suppress("RESERVED_MEMBER_INSIDE_VALUE_CLASS")
+
+import kotlin.test.*
+
+private inline class Z(val data: Int) {
+    override fun equals(other: Any?) = other is Z && data % 256 == other.data % 256
+}
+
+fun box(): String {
+    assertTrue(Z(0) == Z(256))
+    return "OK"
+}