Add test for protocol buffer hash code

test/all_tests.dart

Index: test/all_tests.dart
diff --git a/test/all_tests.dart b/test/all_tests.dart
index ad84c967192418c0bcf8eb49bec7bf52aca44a5e..627b2e36f5d19ab67a972e52e0eb93b74e996cfc 100755
--- a/test/all_tests.dart
+++ b/test/all_tests.dart
@@ -17,6 +17,7 @@ import 'unknown_field_set_test.dart' as ufst;
 import 'validate_fail_test.dart' as vft;
 import 'wire_format_test.dart' as wft;
 import 'reserved_names_test.dart' as rnt;
+import 'hash_code_test.dart' as hct;
 
 void main() {
   egt.main();
@@ -31,4 +32,5 @@ void main() {
   vft.main();
   wft.main();
   rnt.main();
+  hct.main();
 }