JS: move more test to box tests

js/js.translator/testData/box/propertyOverride/overrideExtensionProperty.kt

@@ -0,0 +1,25 @@
+package foo
+
+class T
+
+open class A {
+    open val T.foo: Int
+        get() {
+            return 34
+        }
+    fun test(): Int {
+        return T().foo
+    }
+}
+
+class B : A() {
+    override val T.foo: Int get() = 5
+}
+
+
+fun box(): String {
+    if (A().test() != 34) return "A().test() != 34, it: ${A().test() != 34}"
+    if (B().test() != 5) return "B().test() != 5, it: ${B().test() != 5}"
+
+    return "OK"
+}