Create binstubs for executables when activating a package.

sdk/lib/_internal/pub/test/global/binstubs/reactivate_removes_old_executables_test.dart

Index: sdk/lib/_internal/pub/test/global/binstubs/reactivate_removes_old_executables_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/binstubs/reactivate_removes_old_executables_test.dart b/sdk/lib/_internal/pub/test/global/binstubs/reactivate_removes_old_executables_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..c468d09a05af6f55de2c1dbe45c87173802cd0aa
--- /dev/null
+++ b/sdk/lib/_internal/pub/test/global/binstubs/reactivate_removes_old_executables_test.dart
@@ -0,0 +1,48 @@
+// Copyright (c) 2014, 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 'package:scheduled_test/scheduled_test.dart';
+
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+
+main() {
+  initConfig();
+  integration("removes previous binstubs when reactivating a package", () {
+    d.dir("foo", [
+      d.pubspec({
+        "name": "foo",
+        "executables": {
+          "one": null,
+          "two": null
+        }
+      }),
+      d.dir("bin", [
+        d.file("one.dart", "main() => print('ok');"),
+        d.file("two.dart", "main() => print('ok');")
+      ])
+    ]).create();
+
+    schedulePub(args: ["global", "activate", "--source", "path", "../foo"]);
+
+    d.dir("foo", [
+      d.pubspec({
+        "name": "foo",
+        "executables": {
+          // Remove "one".
+          "two": null
+        }
+      }),
+    ]).create();
+
+    schedulePub(args: ["global", "activate", "--source", "path", "../foo"]);
+
+    d.dir(cachePath, [
+      d.dir("bin", [
+        d.nothing("one"),
+        d.matcherFile("two", contains("two"))
+      ])
+    ]).validate();
+  });
+}