JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/inline/jsCode.kt

@@ -0,0 +1,14 @@
+package foo
+
+// CHECK_CONTAINS_NO_CALLS: test
+
+internal inline fun sum(x: Int, y: Int): Int = js("x + y")
+
+internal fun test(x: Int, y: Int): Int = sum(sum(x, x), sum(y, y))
+
+fun box(): String {
+    assertEquals(4, test(1, 1))
+    assertEquals(8, test(1, 3))
+
+    return "OK"
+}