JVM IR: use a simpler way to check if class is local

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -272,17 +272,6 @@ val IrDeclaration.parentAsClass: IrClass
     get() = parent as? IrClass
         ?: error("Parent of this declaration is not a class: ${render()}")
 
-fun IrClass.isLocalClass(): Boolean {
-    var current: IrDeclarationParent? = this
-    while (current != null && current !is IrPackageFragment) {
-        if (current is IrDeclarationWithVisibility && current.visibility == Visibilities.LOCAL)
-            return true
-        current = (current as? IrDeclaration)?.parent
-    }
-
-    return false
-}
-
 tailrec fun IrElement.getPackageFragment(): IrPackageFragment? {
     if (this is IrPackageFragment) return this
     return when (val parent = (this as? IrDeclaration)?.parent) {