JS: move more test to box tests

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

@@ -0,0 +1,15 @@
+package foo
+
+fun Int.foo() {
+}
+fun String.foo() {
+}
+
+val Int.bar: Int get() = 1
+val String.bar: Int get() = 2
+
+fun box(): String {
+    val a = 43
+    if (a.bar != 1) return "a.bar != 1, it: ${a.bar}"
+    return "OK"
+}