i18n: use test_i18ncmp and test_i18ngrep in t3203, t3501 and t3507

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
index 4ef7d09..6b7c118 100755
--- a/t/t3203-branch-output.sh
+++ b/t/t3203-branch-output.sh
@@ -72,10 +72,10 @@
   branch-two
   master
 EOF
-test_expect_success C_LOCALE_OUTPUT 'git branch shows detached HEAD properly' '
+test_expect_success 'git branch shows detached HEAD properly' '
 	git checkout HEAD^0 &&
 	git branch >actual &&
-	test_cmp expect actual
+	test_i18ncmp expect actual
 '
 
 test_done