Use ":" to separate package and executable name in pub global run.

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

Index: sdk/lib/_internal/pub/test/global/run/unknown_package_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/run/unknown_package_test.dart b/sdk/lib/_internal/pub/test/global/run/unknown_package_test.dart
index 47878124d9f4d23508cc463765ec0c3e9f623103..52a7954c9c340ae38aabab2a4cd3f6e264e9f29f 100644
--- a/sdk/lib/_internal/pub/test/global/run/unknown_package_test.dart
+++ b/sdk/lib/_internal/pub/test/global/run/unknown_package_test.dart
@@ -13,7 +13,7 @@ main() {
   integration('errors if the package is not activated', () {
     servePackages([]);
 
-    schedulePub(args: ["global", "run", "foo", "bar"],
+    schedulePub(args: ["global", "run", "foo:bar"],
         error: startsWith("No active package foo."),
         exitCode: exit_codes.DATA);
   });