[JS IR] Support per-file mode and ES modules

js/js.translator/testData/box/esModules/crossModuleRefPerModule/topLevelProperty.kt

@@ -0,0 +1,50 @@
+// DONT_TARGET_EXACT_BACKEND: JS
+// ES_MODULES
+// SPLIT_PER_MODULE
+// EXPECTED_REACHABLE_NODES: 1287
+// MODULE: lib
+// FILE: lib.kt
+package lib
+
+val foo = 23
+
+val boo: Int
+    get() = 42
+
+external val bar: Int = definedExternally
+
+external val far: Int
+    get() = definedExternally
+
+// TODO: annotations like this are not serialized properly. Uncomment after KT-14529 gets fixed
+/*
+val fuzz: Int
+    @JsName("getBuzz") get() = 55
+    */
+
+inline fun fetchFoo() = foo
+
+@JsName("fee")
+val tee = 2525
+
+// FILE: lib.js
+
+var bar = 99
+var far = 111
+
+// MODULE: main(lib)
+// FILE: lib.kt
+package main
+
+import lib.*
+
+fun box(): String {
+    if (foo != 23) return "fail: simple property: $foo"
+    if (boo != 42) return "fail: property with accessor: $boo"
+    if (bar != 99) return "fail: native property: $bar"
+    if (far != 111) return "fail: native property with accessor: $far"
+    //if (fuzz != 55) return "fail: property with JsName on accessor: $fuzz"
+    if (tee != 2525) return "fail: native property with JsName: $tee"
+
+    return "OK"
+}