Add applicability checks & tests for SubclassOptInRequired

compiler/testData/diagnostics/testsWithStdLib/experimental/subClassOptInModality.kt

@@ -0,0 +1,102 @@
+// FIR_IDENTICAL
+@RequiresOptIn
+annotation class Marker
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+class Final
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+sealed class SealedClass {
+    <!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+    object O : SealedClass()
+}
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+sealed interface SealedInterface
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+fun interface FunInterface {
+    fun doIt()
+}
+
+sealed class Normal
+
+// Ok!
+@SubclassOptInRequired(Marker::class)
+open class NormalOpen : Normal()
+
+// Ok!
+@SubclassOptInRequired(Marker::class)
+abstract class NormalAbstract : Normal()
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+sealed class ErrorSealed : Normal()
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+class ErrorFinal : Normal()
+
+// Ok!
+@SubclassOptInRequired(Marker::class)
+abstract class Abstract
+
+// Error! Should be replaced with OptIn
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+class Derived1 : Abstract()
+
+// Ok!
+@OptIn(Marker::class)
+class Derived2 : Abstract()
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+object Obj
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+enum class E1 {
+    FIRST;
+}
+
+enum class E2 {
+    // Error!
+    <!WRONG_ANNOTATION_TARGET!>@SubclassOptInRequired(Marker::class)<!>
+    SECOND;
+}
+
+// Error!
+<!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+annotation class A
+
+// Local stuff
+fun foo() {
+    // Error!
+    val v = <!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!> object : Any() {
+
+    }
+
+    // Error!
+    <!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+    open class OpenLocal
+
+    // Ok!
+    @OptIn(Marker::class)
+    class DerivedLocal : OpenLocal()
+
+    // Error!
+    <!SUBCLASS_OPT_IN_INAPPLICABLE!>@SubclassOptInRequired(Marker::class)<!>
+    class Local
+}
+
+// Common rules with OptIn
+
+annotation class Simple
+
+// Error! Opt-in marker required
+<!OPT_IN_ARGUMENT_IS_NOT_MARKER!>@SubclassOptInRequired(Simple::class)<!>
+open class Some