JS: move more test to box tests

js/js.translator/testData/box/propertyAccess/field.kt

@@ -0,0 +1,16 @@
+package foo
+
+class A {
+    var a: Int = 0
+        get() = field + 1
+        set(arg) {
+            field = arg
+        }
+}
+
+fun box(): String {
+    val a = A()
+    a.a = 1
+    if (a.a != 2) return "A().a != 2, it: ${a.a}"
+    return "OK"
+}