IR: remove KotlinIrLinker.checkAccessibility

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

compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt

@@ -62,14 +62,5 @@ class JvmIrLinker(
     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 ||
-                            it == JavaVisibilities.PACKAGE_VISIBILITY || it == JavaVisibilities.PROTECTED_AND_PACKAGE
-                }
-    }
-
     private val ModuleDescriptor.userName get() = kotlinLibrary.libraryFile.absolutePath
 }