Support activating packages from local paths.

sdk/lib/_internal/pub/test/global/run/reflects_changes_to_local_package_test.dart

Index: sdk/lib/_internal/pub/test/global/run/reflects_changes_to_local_package_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/run/implicit_executable_name_test.dart b/sdk/lib/_internal/pub/test/global/run/reflects_changes_to_local_package_test.dart
similarity index 52%
copy from sdk/lib/_internal/pub/test/global/run/implicit_executable_name_test.dart
copy to sdk/lib/_internal/pub/test/global/run/reflects_changes_to_local_package_test.dart
index ad93bac7e2e8e346542b8c95f68b77347f1d4bd6..9fc5b4e18e8069b6384fb2775ff9e28dca3e1a37 100644
--- a/sdk/lib/_internal/pub/test/global/run/implicit_executable_name_test.dart
+++ b/sdk/lib/_internal/pub/test/global/run/reflects_changes_to_local_package_test.dart
@@ -2,25 +2,26 @@
 // 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 '../../../lib/src/exit_codes.dart' as exit_codes;
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
   initConfig();
-  integration('defaults to the package name if the script is omitted', () {
-    servePackages([
-      packageMap("foo", "1.0.0")
-    ], contents: [
+  integration('changes in a path package are immediately reflected',
+      () {
+    d.dir("foo", [
+      d.libPubspec("foo", "1.0.0"),
       d.dir("bin", [
-        d.file("foo.dart", "main(args) => print('foo');")
+        d.file("foo.dart", "main() => print('ok');")
       ])
-    ]);
+    ]).create();
 
-    schedulePub(args: ["global", "activate", "foo"]);
+    schedulePub(args: ["global", "activate", "--source", "path", "../foo"]);
+
+    d.file("foo/bin/foo.dart", "main() => print('changed');").create();
 
     var pub = pubRun(global: true, args: ["foo"]);
-    pub.stdout.expect("foo");
+    pub.stdout.expect("changed");
     pub.shouldExit();
   });
 }