K2 opt-in: drop redundant recursive check for overridables

compiler/testData/diagnostics/testsWithStdLib/experimental/overridableCheck.fir.kt

@@ -0,0 +1,22 @@
+@RequiresOptIn
+@Target(AnnotationTarget.TYPEALIAS, AnnotationTarget.FUNCTION)
+annotation class Marker
+
+class Wrapper<T>
+
+@Marker
+typealias TA<T> = Wrapper<T>
+
+open class Base<T> {
+    @Marker
+    open fun foo(): T? = null
+
+    open fun bar(): <!OPT_IN_USAGE_ERROR!>TA<T><!>? = null
+}
+
+class Derived : Base<String>()
+
+fun test(d: Derived) {
+    d.<!OPT_IN_USAGE_ERROR!>foo<!>()
+    d.<!OPT_IN_USAGE_ERROR!>bar<!>()
+}

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

@@ -0,0 +1,22 @@
+@RequiresOptIn
+@Target(AnnotationTarget.TYPEALIAS, AnnotationTarget.FUNCTION)
+annotation class Marker
+
+class Wrapper<T>
+
+@Marker
+typealias TA<T> = Wrapper<T>
+
+open class Base<T> {
+    @Marker
+    open fun foo(): T? = null
+
+    open fun bar(): <!OPT_IN_USAGE_ERROR!>TA<!><T>? = null
+}
+
+class Derived : Base<String>()
+
+fun test(d: Derived) {
+    d.<!OPT_IN_USAGE_ERROR!>foo<!>()
+    d.<!OPT_IN_USAGE_ERROR!>bar<!>()
+}

compiler/testData/diagnostics/testsWithStdLib/experimental/overridableCheck.txt

@@ -0,0 +1,36 @@
+package
+
+public fun test(/*0*/ d: Derived): kotlin.Unit
+
+public open class Base</*0*/ T> {
+    public constructor Base</*0*/ T>()
+    public open fun bar(): TA<T>? /* = Wrapper<T>? */
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @Marker public open fun foo(): T?
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Derived : Base<kotlin.String> {
+    public constructor Derived()
+    public open override /*1*/ /*fake_override*/ fun bar(): TA<kotlin.String>? /* = Wrapper<kotlin.String>? */
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @Marker public open override /*1*/ /*fake_override*/ fun foo(): kotlin.String?
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+@kotlin.RequiresOptIn @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.TYPEALIAS, AnnotationTarget.FUNCTION}) public final annotation class Marker : kotlin.Annotation {
+    public constructor Marker()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Wrapper</*0*/ T> {
+    public constructor Wrapper</*0*/ T>()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+@Marker public typealias TA</*0*/ T> = Wrapper<T>