Upgrade "path" package to 1.4.1 and eliminate analyzer test workaround.

pkg/analyzer/test/src/summary/resynthesize_common.dart

 // Copyright (c) 2015, 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.
 
 library test.src.serialization.elements_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 3429 matching lines @@
 class C {}
 class D extends p.C {} // Prevent "unused import" warning
 ''');
     expect(resynthesized.imports, hasLength(2));
     expect(resynthesized.imports[0].importedLibrary.location,
         resynthesized.location);
     expect(resynthesized.imports[1].importedLibrary.isDartCore, true);
   }
 
   test_import_short_absolute() {
-    if (resourceProvider.pathContext.separator == '\\') {
-      // This test fails on Windows due to
-      // https://github.com/dart-lang/path/issues/18
-      // TODO(paulberry): reenable once that bug is addressed.
-      return;
-    }
     testFile = '/my/project/bin/test.dart';
-    addLibrarySource('/a.dart', 'class C {}');
+    // Note: "/a.dart" resolves differently on Windows vs. Posix.
+    var destinationPath =
+        resourceProvider.pathContext.fromUri(Uri.parse('/a.dart'));
+    addLibrarySource(destinationPath, 'class C {}');
     checkLibrary('import "/a.dart"; C c;');
   }
 
   test_import_show() {
     addLibrary('dart:async');
     checkLibrary('''
 import "dart:async" show Future, Stream;
 Future f;
 Stream s;
 ''');
@@ skipping 1371 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }