Make pub's binstubs resilient to changes in snapshot format.

sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart

Index: sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart
diff --git a/sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart b/sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart
index e52a1ebdfcd0798cb3595d6317ae0aba7930ccaf..7e1a7ae98bc164ca116c76f7cc3486fcd67c8813 100644
--- a/sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart
+++ b/sdk/lib/_internal/pub_generated/test/global/binstubs/utils.dart
@@ -2,12 +2,42 @@
 // 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:async';
 import 'dart:io';
 
-/// Returns the name of the shell script for a binstub named [name].
-///
-/// Adds a ".bat" extension on Windows.
-binStubName(String name) {
-  if (Platform.operatingSystem == "windows") return "$name.bat";
-  return name;
+import 'package:path/path.dart' as p;
+
+import '../../test_pub.dart';
+
+/// The buildbots do not have the Dart SDK (containing "dart" and "pub") on
+/// their PATH, so we need to spawn the binstub process with a PATH that
+/// explicitly includes it.
+Future<Map> getEnvironment() {
+  final completer0 = new Completer();
+  scheduleMicrotask(() {
+    try {
+      var binDir = p.dirname(Platform.executable);
+      join0(x0) {
+        var separator = x0;
+        var path = "${Platform.environment["PATH"]}${separator}${binDir}";
+        getPubTestEnvironment().then((x1) {
+          try {
+            var environment = x1;
+            environment["PATH"] = path;
+            completer0.complete(environment);
+          } catch (e0, s0) {
+            completer0.completeError(e0, s0);
+          }
+        }, onError: completer0.completeError);
+      }
+      if (Platform.operatingSystem == "windows") {
+        join0(";");
+      } else {
+        join0(":");
+      }
+    } catch (e, s) {
+      completer0.completeError(e, s);
+    }
+  });
+  return completer0.future;
 }