KT-2752: add checkers for inconsistent usage of JsName

js/js.translator/testData/box/nameClashes/propertyAndNativeMethod.kt

@@ -0,0 +1,16 @@
+package foo
+
+@native fun bar()
+
+val bar = 32
+
+fun createNativeBar() = js("bar = function() { return 23; };")
+
+fun box(): String {
+    createNativeBar()
+
+    assertEquals(23, bar())
+    assertEquals(32, bar)
+
+    return "OK"
+}