JS: add some tests to ensure that AST metadata is correctly serialized and deserialized and visible to JS optimizer

js/js.translator/testData/box/incremental/defaultArguments.kt

@@ -0,0 +1,14 @@
+// FILE: a.kt
+
+inline fun foo(f: (Int) -> String, x: Int = 23): String = "foo(${f(x)})"
+
+
+// FILE: b.kt
+// RECOMPILE
+
+fun box(): String {
+    val result = foo({ it.toString() }) + foo({ it.toString() }, 42)
+    if (result != "foo(23)foo(42)") return "fail: $result"
+
+    return "OK"
+}