[K/JS] Support companion objects in external and exported declarations

js/js.translator/testData/box/esModules/jsModule/interfacesWithCompanion.kt

@@ -0,0 +1,20 @@
+// TARGET_BACKEND: JS_IR
+// TARGET_BACKEND: JS_IR_ES6
+// EXPECTED_REACHABLE_NODES: 1238
+// ES_MODULES
+// FILE: bar.kt
+@file:JsModule("./interfacesWithCompanion.mjs")
+package bar
+
+external interface Bar {
+    companion object {
+        fun ok(): String
+    }
+}
+
+// FILE: test.kt
+import bar.Bar
+
+fun box(): String {
+    return Bar.ok()
+}

js/js.translator/testData/box/esModules/jsModule/interfacesWithCompanion.mjs

@@ -0,0 +1,3 @@
+export const Bar = {
+    ok() { return "OK" }
+};