Add “pub cache repair” to forcibly re-install previously cached packages.

sdk/lib/_internal/pub/test/pub_test.dart

Index: sdk/lib/_internal/pub/test/pub_test.dart
diff --git a/sdk/lib/_internal/pub/test/pub_test.dart b/sdk/lib/_internal/pub/test/pub_test.dart
index a7af4aadbf06fab06547a78133bb7fd4b852f15b..168008c90c8a5b397af50722726df22e91bf7f9d 100644
--- a/sdk/lib/_internal/pub/test/pub_test.dart
+++ b/sdk/lib/_internal/pub/test/pub_test.dart
@@ -93,7 +93,8 @@ main() {
           -h, --help    Print usage information for this command.
 
           Available subcommands:
-            add   Install a package.
+            add      Install a package.
+            repair   Reinstall cached packages.
      ''');
   });
 
@@ -131,7 +132,8 @@ main() {
         -h, --help    Print usage information for this command.
 
         Available subcommands:
-          add   Install a package.
+          add      Install a package.
+          repair   Reinstall cached packages.
         ''',
         exitCode: exit_codes.USAGE);
   });
@@ -176,7 +178,8 @@ main() {
         -h, --help    Print usage information for this command.
 
         Available subcommands:
-          add   Install a package.
+          add      Install a package.
+          repair   Reinstall cached packages.
         ''',
         exitCode: exit_codes.USAGE);
   });
@@ -277,7 +280,8 @@ main() {
             -h, --help    Print usage information for this command.
 
             Available subcommands:
-              add   Install a package.
+              add      Install a package.
+              repair   Reinstall cached packages.
             ''',
             exitCode: exit_codes.USAGE);
     });