sdk files reorganization to make dart2js a proper package

sdk/lib/_internal/compiler/js_lib/js_primitives.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/// dart2js "primitives", that is, features that cannot be implemented without
-/// access to JavaScript features.
-library dart2js._js_primitives;
-
-import 'dart:_foreign_helper' show
-    JS;
-
-/**
- * This is the low-level method that is used to implement [print].  It is
- * possible to override this function from JavaScript by defining a function in
- * JavaScript called "dartPrint".
- *
- * Notice that it is also possible to intercept calls to [print] from within a
- * Dart program using zones. This means that there is no guarantee that a call
- * to print ends in this method.
- */
-void printString(String string) {
-  if (JS('bool', r'typeof dartPrint == "function"')) {
-    // Support overriding print from JavaScript.
-    JS('void', r'dartPrint(#)', string);
-    return;
-  }
-
-  // Inside browser or nodejs.
-  if (JS('bool', r'typeof console == "object"') &&
-      JS('bool', r'typeof console.log != "undefined"')) {
-    JS('void', r'console.log(#)', string);
-    return;
-  }
-
-  // Don't throw inside IE, the console is only defined if dev tools is open.
-  if (JS('bool', r'typeof window == "object"')) {
-    return;
-  }
-
-  // Running in d8, the V8 developer shell, or in Firefox' js-shell.
-  if (JS('bool', r'typeof print == "function"')) {
-    JS('void', r'print(#)', string);
-    return;
-  }
-
-  // This is somewhat nasty, but we don't want to drag in a bunch of
-  // dependencies to handle a situation that cannot happen. So we
-  // avoid using Dart [:throw:] and Dart [toString].
-  JS('void', 'throw "Unable to print message: " + String(#)', string);
-}