KT-4107 Data objects

compiler/testData/codegen/box/dataObjects/multipleInstances.kt

@@ -0,0 +1,18 @@
+// LANGUAGE: +DataObjects
+// WITH_STDLIB
+// TARGET_BACKEND: JVM_IR
+
+import kotlin.test.*
+
+data object DataObject
+
+val doppelganger = DataObject::class.java.declaredConstructors[0].apply { isAccessible = true }.newInstance()
+
+fun box(): String {
+    assertFalse(DataObject === doppelganger)
+    assertEquals(DataObject, doppelganger)
+    assertEquals(DataObject.hashCode(), DataObject::class.java.cast(doppelganger).hashCode())
+
+    return  "OK"
+}
+