Add script attribute to Options class, providing the name of the running script.

tests/standalone/src/OptionsTest.dart

Index: tests/standalone/src/OptionsTest.dart
diff --git a/tests/standalone/src/OptionsTest.dart b/tests/standalone/src/OptionsTest.dart
index caf0e123fe58969dd347cdf434cb0cfe9a1eb4a6..174c28df8faa2e6db80cfca6f7c6e772807bfe17 100644
--- a/tests/standalone/src/OptionsTest.dart
+++ b/tests/standalone/src/OptionsTest.dart
@@ -12,6 +12,8 @@ main() {
   Expect.equals(10, Math.parseInt(opts.arguments[0]));
   Expect.equals("OptionsTest", opts.arguments[1]);
   Expect.equals(20, Math.parseInt(opts.arguments[2]));
+  Expect.isTrue(opts.script.replaceAll('\\', '/').
+                endsWith('tests/standalone/src/OptionsTest.dart'));
 
   // Now add an additional argument.
   opts.arguments.add("Fourth");