K/N: Use class FQN in default toString() implementation

^KT-47167

kotlin-native/backend.native/tests/runtime/basic/tostring4.kt

@@ -0,0 +1,33 @@
+/*
+ * 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.
+ */
+
+package runtime.basic.tostring4
+
+import kotlin.test.*
+
+class TopLevel
+
+@Test fun runTest() {
+    assertEquals("runtime.basic.tostring4.TopLevel", TopLevel().toStringWithoutHashCode())
+
+    class Local1
+    assertEquals("runtime.basic.tostring4.runTest\$Local1", Local1().toStringWithoutHashCode())
+
+    assertEquals("runtime.basic.tostring4.runTest\$1", object {}.toStringWithoutHashCode())
+
+    fun localFun() {
+        class Local2
+        assertEquals("runtime.basic.tostring4.runTest\$localFun\$Local2", Local2().toStringWithoutHashCode())
+
+        assertEquals("runtime.basic.tostring4.runTest\$localFun\$1", object {}.toStringWithoutHashCode())
+    }
+    localFun()
+}
+
+private fun Any.toStringWithoutHashCode(): String {
+    val string = toString()
+    assertEquals(1, string.count { it == '@' }, "Invalid toString() value: $string")
+    return string.substringBefore('@')
+}