Possible fix for Windows bot failures

pkg/analysis_server/lib/src/context_manager.dart

Index: pkg/analysis_server/lib/src/context_manager.dart
diff --git a/pkg/analysis_server/lib/src/context_manager.dart b/pkg/analysis_server/lib/src/context_manager.dart
index a4e5849dc9b2b84946df3dd5c906d87bdd5fcee2..2d4d08faed6b2d8ccdea7b518c133d63c69f517f 100644
--- a/pkg/analysis_server/lib/src/context_manager.dart
+++ b/pkg/analysis_server/lib/src/context_manager.dart
@@ -768,7 +768,7 @@ class ContextManagerImpl implements ContextManager {
       try {
         if (ENABLE_PACKAGESPEC_SUPPORT) {
           // Try .packages first.
-          if (pathos.basename(packagespecFile.path) == PACKAGE_SPEC_NAME) {
+          if (pathContext.basename(packagespecFile.path) == PACKAGE_SPEC_NAME) {
             Packages packages = _readPackagespec(packagespecFile);
             return new PackagesFileDisposition(packages);
           }
@@ -1018,7 +1018,7 @@ class ContextManagerImpl implements ContextManager {
               if (_isPubspec(path)) {
                 // Check for a sibling .packages file.
                 if (!resourceProvider
-                    .getFile(pathos.join(directoryPath, PACKAGE_SPEC_NAME))
+                    .getFile(pathContext.join(directoryPath, PACKAGE_SPEC_NAME))
                     .exists) {
                   _extractContext(info, resource);
                   return;
@@ -1027,7 +1027,7 @@ class ContextManagerImpl implements ContextManager {
               if (_isPackagespec(path)) {
                 // Check for a sibling pubspec.yaml file.
                 if (!resourceProvider
-                    .getFile(pathos.join(directoryPath, PUBSPEC_NAME))
+                    .getFile(pathContext.join(directoryPath, PUBSPEC_NAME))
                     .exists) {
                   _extractContext(info, resource);
                   return;
@@ -1073,7 +1073,7 @@ class ContextManagerImpl implements ContextManager {
               if (_isPubspec(path)) {
                 // Check for a sibling .packages file.
                 if (!resourceProvider
-                    .getFile(pathos.join(directoryPath, PACKAGE_SPEC_NAME))
+                    .getFile(pathContext.join(directoryPath, PACKAGE_SPEC_NAME))
                     .exists) {
                   _mergeContext(info);
                   return;
@@ -1082,7 +1082,7 @@ class ContextManagerImpl implements ContextManager {
               if (_isPackagespec(path)) {
                 // Check for a sibling pubspec.yaml file.
                 if (!resourceProvider
-                    .getFile(pathos.join(directoryPath, PUBSPEC_NAME))
+                    .getFile(pathContext.join(directoryPath, PUBSPEC_NAME))
                     .exists) {
                   _mergeContext(info);
                   return;