JS: move more test to box tests

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

@@ -0,0 +1,11 @@
+package foo
+
+class Test() {
+    var a: Int = 100
+}
+
+fun box(): String {
+    var test = Test()
+    test.a = 1
+    return if (1 == test.a) "OK" else "fail: ${test.a}"
+}