bench.pl: Load IO::File explicitly

to work with older perls that don’t load it automatically.

$ Porting/bench.pl perl5.8.8 perl5.8.7
Can't locate object method "blocking" via package "IO::File" at Porting/bench.pl line 737.

(In this case the system perl is 5.12.4.)

1 files changed, 1 insertions, 0 deletions

diff --git a/Porting/bench.pl b/Porting/bench.pl
index bbc1247252..dc90a8ff19 100755
--- a/Porting/bench.pl
+++ b/Porting/bench.pl
@@ -205,6 +205,7 @@ use strict;
 use Getopt::Long qw(:config no_auto_abbrev);
 use IPC::Open2 ();
 use IO::Select;
+use IO::File;
 use POSIX ":sys_wait_h";
 
 # The version of the file format used to save data. We refuse to process