Add an ArgResults.original getter.

pkg/args/lib/src/parser.dart

Index: pkg/args/lib/src/parser.dart
diff --git a/pkg/args/lib/src/parser.dart b/pkg/args/lib/src/parser.dart
index 4d3417a12599df4b323b9e120f5501db597c65b1..9cd141c00a334b63b6ac491d5c38deb05aea510b 100644
--- a/pkg/args/lib/src/parser.dart
+++ b/pkg/args/lib/src/parser.dart
@@ -46,6 +46,7 @@ class Parser {
 
   /// Parses the arguments. This can only be called once.
   ArgResults parse() {
+    var arguments = args.toList();
     var commandResults = null;
 
     // Parse the args.
@@ -91,7 +92,8 @@ class Parser {
     // Add in the leftover arguments we didn't parse to the innermost command.
     rest.addAll(args);
     args.clear();
-    return newArgResults(grammar, results, commandName, commandResults, rest);
+    return newArgResults(grammar, results, commandName, commandResults, rest,
+        arguments);
   }
 
   /// Pulls the value for [option] from the second argument in [args].