Revert "Reapply fast-URI patch."

pkg/analyzer/lib/src/util/fast_uri.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:collection';
 
 /**
  * Implementation of [Uri] that understands only a limited set of valid
  * URI formats, but works fast. In practice Dart code almost always uses such
  * limited URI format, so almost always can be processed fast.
@@ skipping 44 matching lines @@
   @override
   bool get hasAuthority => _hasEmptyAuthority;
 
   @override
   bool get hasEmptyPath => _path.isEmpty;
 
   @override
   bool get hasFragment => false;
 
   @override
-  int get hashCode => _text.hashCode;
+  int get hashCode {
+    // This code is copied from the standard Uri implementation.
+    // It is important that Uri and FastUri generate compatible hashCodes
+    // because Uri and FastUri may be used as keys in the same map.
+    int combine(part, current) {
+      // The sum is truncated to 30 bits to make sure it fits into a Smi.
+      return (current * 31 + part.hashCode) & 0x3FFFFFFF;
+    }
+    return _hashCode ??= combine(
+        scheme,
+        combine(
+            userInfo,
+            combine(
+                host,
+                combine(port,
+                    combine(path, combine(query, combine(fragment, 1)))))));
+  }
 
   @override
   bool get hasPort => false;
 
   @override
   bool get hasQuery => false;
 
   @override
   bool get hasScheme => _scheme.isNotEmpty;
 
@@ skipping 190 matching lines @@
       hasEmptyAuthority = true;
       path = path.substring(2);
       if (!path.startsWith('/')) {
         return null;
       }
     }
     return new FastUri._(_currentCacheGeneration, text, scheme,
         hasEmptyAuthority, path, lastSlashIndex);
   }
 }