[JS IR BE] Support cast to native interface

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

@@ -218,7 +218,13 @@ class TypeOperatorLowering(val context: JsIrBackendContext) : FileLoweringPass {
                     toType.isArray() -> generateGenericArrayCheck(argument)
                     toType.isPrimitiveArray() -> generatePrimitiveArrayTypeCheck(argument, toType)
                     toType.isTypeParameter() -> generateTypeCheckWithTypeParameter(argument, toType)
-                    toType.isInterface() -> generateInterfaceCheck(argument, toType)
+                    toType.isInterface() -> {
+                        if ((toType.classifierOrFail.owner as IrClass).isEffectivelyExternal()) {
+                            generateIsObjectCheck(argument)
+                        } else {
+                            generateInterfaceCheck(argument, toType)
+                        }
+                    }
                     else -> generateNativeInstanceOf(argument, toType)
                 }
             }

js/js.translator/testData/box/native/castToNativeInterface.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1282
 // FILE: castToNativeInterface.kt
 external interface I {

js/js.translator/testData/box/native/castToTypeParamBoundedByNativeInterface.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1284
 // FILE: castToTypeParamBoundedByNativeInterface.kt
 external interface I {