Method can be hidden if it is annotated with kotlin.internal.PlatformDependent,

or is a Java method from a Kotlin built-in class (transitively).

https://github.com/Kotlin/KEEP/blob/master/proposals/jdk-dependent-built-ins.md#backward-compatibility-of-overrides

compiler/testData/diagnostics/testsWithJava8/targetedBuiltIns/backwardCompatibility/finalize.kt

@@ -0,0 +1,10 @@
+enum class TestEnum {
+    ENTRY;
+
+    <!VIRTUAL_MEMBER_HIDDEN!>fun getDeclaringClass()<!> {}
+    <!VIRTUAL_MEMBER_HIDDEN!>fun finalize()<!> {}
+}
+
+class TestFinalize {
+    fun finalize() {}
+}