JS: move more test to box tests

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

@@ -0,0 +1,14 @@
+package foo
+
+class Test() {
+    var a: Int = 5
+        set(b: Int) {
+            field = 3
+        }
+}
+
+fun box(): String {
+    var test = Test()
+    test.a = 5
+    return if (test.a == 3) "OK" else "fail: ${test.a}"
+}