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

js/js.translator/testData/box/char/charEquals.kt

@@ -0,0 +1,12 @@
+package foo
+
+class A
+
+fun box(): String {
+
+    assertEquals(true, 'A' == 'A')
+    assertEquals(false, 'A'== 'B')
+    assertEquals(false, ('A' as Any) == (65 as Any))
+
+    return "OK"
+}