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

DEPS

 # 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.
 
 vars = {
   # The dart_root is the root of our sdk checkout. This is normally
   # simply sdk, but if using special gclient specs it can be different.
   "dart_root": "sdk",
 
   # We use mirrors of all github repos to guarantee reproducibility and
@@ skipping 67 matching lines @@
   "markdown_tag": "@0.11.0",
   "matcher_tag": "@0.12.0+2",
   "metatest_tag": "@0.2.2+2",
   "mime_rev": "@75890811d4af5af080351ba8a2853ad4c8df98dd",
   "mustache4dart_tag" : "@v1.0.10",
   "oauth2_tag": "@1.0.2",
   "observatory_pub_packages_rev": "@26aad88f1c1915d39bbcbff3cad589e2402fdcf1",
   "observe_tag": "@0.13.5",
   "package_config_tag": "@1.0.0",
   "package_resolver_tag": "@1.0.2",
-  "path_tag": "@1.3.9",
+  "path_tag": "@1.4.1",
   "plugin_tag": "@0.2.0",
   "ply_rev": "@604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_tag": "@1.2.4",
   "protobuf_tag": "@0.5.3",
   "pub_rev": "@9309be93140638fb19903648d07de59681a08989",
   "pub_semver_tag": "@1.3.0",
   "quiver_tag": "@0.22.0",
   "resource_rev":"@a49101ba2deb29c728acba6fb86000a8f730f4b1",
   "root_certificates_rev": "@aed07942ce98507d2be28cbd29e879525410c7fc",
   "scheduled_test_tag": "@0.12.6",
@@ skipping 493 matching lines @@
     # Update the Windows toolchain if necessary.
     'name': 'win_toolchain',
     'pattern': '.',
     'action': ['python', 'sdk/build/vs_toolchain.py', 'update'],
   },
   {
     "pattern": ".",
     "action": ["python", Var("dart_root") + "/tools/generate_buildfiles.py"],
   },
 ]