Move js library back into compiler directory.

sdk/lib/_internal/compiler/implementation/warnings.dart

 // Copyright (c) 2011, 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.
 
 part of dart2js;
 
 const DONT_KNOW_HOW_TO_FIX = "";
 
 /**
  * The messages in this file should meet the following guide lines:
@@ skipping 1947 matching lines @@
 
   static const MessageKind HIDDEN_WARNINGS = const MessageKind(
       "#{warnings} warning(s) suppressed in #{uri}.");
 
   static const MessageKind HIDDEN_HINTS = const MessageKind(
       "#{hints} hint(s) suppressed in #{uri}.");
 
   static const MessageKind PREAMBLE = const MessageKind(
     "When run on the command-line, the compiled output might"
     " require a preamble file located in:\n"
-    "  <sdk>/lib/_internal/lib/preambles.");
+    "  <sdk>/lib/_internal/complire/js_lib/preambles.");
 
   //////////////////////////////////////////////////////////////////////////////
   // Patch errors start.
   //////////////////////////////////////////////////////////////////////////////
 
   static const MessageKind PATCH_RETURN_TYPE_MISMATCH = const MessageKind(
       "Patch return type '#{patchReturnType}' does not match "
       "'#{originReturnType}' on origin method '#{methodName}'.");
 
   static const MessageKind PATCH_REQUIRED_PARAMETER_COUNT_MISMATCH =
@@ skipping 141 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }