JS: report errors on different external items:

* data classes
* val/var parameters of primary constructors
* enum entry with body
* anonymous `init {}` block in classes

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

@@ -1,6 +1,8 @@
 package foo
 
-external class A(val v: String) {
+external class A(v: String) {
+    val v: String
+
     fun m(i:Int, s:String): String = noImpl
 }