Make RegExp's constructor non-const.

utils/pub/io.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Helper functionality to make working with IO easier.
  */
 library io;
 
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:uri';
 
 import 'utils.dart';
 
 bool _isGitInstalledCache;
 
 /// The cached Git command.
 String _gitCommandCache;
 
 /** Gets the current working directory. */
 String get currentWorkingDir => new File('.').fullPathSync();
 
-const Pattern NEWLINE_PATTERN = const RegExp("\r\n?|\n\r?");
+final Pattern NEWLINE_PATTERN = new RegExp("\r\n?|\n\r?");
 
 /**
  * Prints the given string to `stderr` on its own line.
  */
 void printError(value) {
   stderr.writeString(value.toString());
   stderr.writeString('\n');
 }
 
 /**
@@ skipping 340 matching lines @@
 
 /// Given [entry] which may be a [String], [File], or [Directory] relative to
 /// the current working directory, returns its full canonicalized path.
 String getFullPath(entry) {
   var path = _getPath(entry);
 
   // Don't do anything if it's already absolute.
   if (Platform.operatingSystem == 'windows') {
     // An absolute path on Windows is either UNC (two leading backslashes),
     // or a drive letter followed by a colon and a slash.
-    const ABSOLUTE = const RegExp(r'^(\\\\|[a-zA-Z]:[/\\])');
+    final ABSOLUTE = new RegExp(r'^(\\\\|[a-zA-Z]:[/\\])');
     if (ABSOLUTE.hasMatch(path)) return path;
   } else {
     if (path.startsWith('/')) return path;
   }
 
   // Using Path.join here instead of File().fullPathSync() because the former
   // does not require an actual file to exist at that path.
   return new Path.fromNative(currentWorkingDir).join(new Path(path))
       .toNativePath();
 }
@@ skipping 379 matching lines @@
   return new Directory(entry);
 }
 
 /**
  * Gets a [Uri] for [uri], which can either already be one, or be a [String].
  */
 Uri _getUri(uri) {
   if (uri is Uri) return uri;
   return new Uri.fromString(uri);
 }