[PATCH 3/4] t/hl_mod: document IO::Handle for autoflush

[Eric Wong <e@yhbt.net>]

We don't need IO::File for this test, but IO::Handle
is needed for ->autoflush with Perl <5.14.

Note: I haven't tested highlight.pm under 5.10.1 since
it's a weird dependency which isn't easy to install w/o
distro support.
---
 t/hl_mod.t | 1 +
 1 file changed, 1 insertion(+)

diff --git a/t/hl_mod.t b/t/hl_mod.t
index 4942404c..351dfe22 100644
--- a/t/hl_mod.t
+++ b/t/hl_mod.t
@@ -5,6 +5,7 @@ use strict;
 use warnings;
 use Test::More;
 use PublicInbox::Spawn qw(which spawn);
+use IO::Handle; # ->autoflush
 use Fcntl qw(:seek);
 eval { require highlight } or
 	plan skip_all => "failed to load highlight.pm for $0";