IR: remove KotlinIrLinker.checkAccessibility

This sanity check conflicted with cases where visibility test is
suppressed in the frontend.

compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrLinker.kt

@@ -51,10 +51,5 @@ class JsIrLinker(
     override fun readFileCount(moduleDescriptor: ModuleDescriptor) =
         moduleDescriptor.kotlinLibrary.fileCount()
 
-    override fun checkAccessibility(declarationDescriptor: DeclarationDescriptor): Boolean {
-        require(declarationDescriptor is DeclarationDescriptorWithVisibility)
-        return declarationDescriptor.isPublishedApi() || declarationDescriptor.visibility.let { it.isPublicAPI || it == Visibilities.INTERNAL }
-    }
-
     private val ModuleDescriptor.userName get() = kotlinLibrary.libraryFile.absolutePath
 }