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

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/JsPlatformConfigurator.kt

@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.js.resolve.diagnostics.*
 import org.jetbrains.kotlin.platform.PlatformToKotlinClassMap
 import org.jetbrains.kotlin.resolve.IdentifierChecker
 import org.jetbrains.kotlin.resolve.OverloadFilter
+import org.jetbrains.kotlin.resolve.OverridesBackwardCompatibilityHelper
 import org.jetbrains.kotlin.resolve.PlatformConfigurator
 import org.jetbrains.kotlin.resolve.calls.checkers.ReifiedTypeParameterSubstitutionChecker
 import org.jetbrains.kotlin.resolve.checkers.HeaderImplDeclarationChecker
@@ -47,7 +48,8 @@ object JsPlatformConfigurator : PlatformConfigurator(
         identifierChecker = IdentifierChecker.DEFAULT,
         overloadFilter = OverloadFilter.DEFAULT,
         platformToKotlinClassMap = PlatformToKotlinClassMap.EMPTY,
-        delegationFilter = DelegationFilter.DEFAULT
+        delegationFilter = DelegationFilter.DEFAULT,
+        overridesBackwardCompatibilityHelper = OverridesBackwardCompatibilityHelper.DEFAULT
 ) {
     override fun configureModuleComponents(container: StorageComponentContainer) {
         container.useImpl<JsCallChecker>()