[K/JS] Add file-to-file compilation ^KT-6168 Fixed

js/js.translator/testData/box/esModules/jsExport/perFileExportedApi.kt

@@ -0,0 +1,39 @@
+// DONT_TARGET_EXACT_BACKEND: JS
+// SKIP_MINIFICATION
+// ES_MODULES
+// SPLIT_PER_FILE
+
+// FILE: base.kt
+
+@JsExport
+open class Base() {
+    var bar = "bar"
+    fun foo() = "foo"
+}
+
+// FILE: a.kt
+
+@JsExport
+class A : Base() {
+    val pong = "pong"
+    fun ping() = "ping"
+}
+
+// FILE: function.kt
+
+@JsExport
+fun create() = A()
+
+// FILE: main.kt
+@JsModule("./perFileExportedApi.mjs")
+external fun jsBox(): String
+
+fun box(): String {
+    val res = jsBox()
+
+    if (res != "bar&not bar&foo&ping&pong") {
+        return "Fail: ${res}"
+    }
+
+    return "OK"
+}

js/js.translator/testData/box/esModules/jsExport/perFileExportedApi.mjs

@@ -0,0 +1,15 @@
+import { create } from "./perFileExportedApi-kotlin_main_v5/function.export.mjs";
+
+export default function() {
+    let result = ""
+    const a = create()
+
+    result += a.bar
+    a.bar = "not bar"
+    result += `&${a.bar}`
+    result += `&${a.foo()}`
+    result += `&${a.ping()}`
+    result += `&${a.pong}`
+
+    return result
+};