Prohibit data classes with no primary constructor

compiler/testData/diagnostics/tests/secondaryConstructors/dataClasses.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+data class A1(val x: String) {
+    constructor(): this("") {}
+}
+
+data class A2() {
+    constructor(x: String): this() {}
+}
+
+data class <!PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS!>A3<!> {
+    constructor() {}
+}