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

js/js.translator/testData/box/closure/closureThisInLambdaInsideMethod.kt

@@ -0,0 +1,17 @@
+// KT-4207 Closure this doesn't work in JS backend
+
+package foo
+
+fun String.foo() = { this }
+
+class A {
+    fun foo() = { this }
+    val ok = "OK"
+}
+
+fun box(): String {
+    if ("OK".foo()() != "OK") return "\"OK\".foo()() != \"OK\""
+    if (A().foo()().ok != "OK") return "A().foo()().ok != \"OK\""
+
+    return "OK"
+}