Less utf8 encode/decode (just decode immediately)

Better than it was, but there are still ways to improve the code.
For example, currently it may throw up on non-UTF8 data, which is less than
awesome for git bisect (we do not want to care if it is correct UTF-8 or not,
we just want to bisect).

Perl6IRCBotable.pm

@@ -52,7 +52,7 @@ sub get_output {
   my $s_start = time();
   my $pid = open3(undef, \*RESULT, \*RESULT, @_);
   {
-    local $SIG{ALRM} = sub { kill 9, $pid; $out = encode_utf8("«timed out after $wait seconds, output»: "); };
+    local $SIG{ALRM} = sub { kill 9, $pid; $out = "«timed out after $wait seconds, output»: " };
     alarm $wait;
     waitpid($pid, 0);
     alarm 0;
@@ -62,7 +62,7 @@ sub get_output {
   my $exit_status = $? >> 8;
   my $exit_signal = $? & 127;
 
-  $out .= do { local $/; <RESULT> } // '';
+  $out .= decode_utf8(do { local $/; <RESULT> }) // ''; # assume UTF-8, that's the best we can do
   chomp $out;
 
   return ($out, $exit_status, $exit_signal, $s_end - $s_start)

benchable.pl

@@ -25,7 +25,7 @@ package Benchable;
 use parent 'Perl6IRCBotable';
 
 use Cwd qw(cwd abs_path);
-use Encode qw(encode_utf8 decode_utf8);
+use Encode qw(encode_utf8);
 use File::Temp qw(tempfile tempdir);
 use List::Util qw(min max);
 use Chart::Gnuplot;

bisectable.pl

@@ -24,7 +24,6 @@
 package Bisectable;
 use parent 'Perl6IRCBotable';
 
-use Encode qw(decode_utf8);
 use File::Temp qw(tempfile tempdir);
 use Cwd qw(cwd abs_path);
 
@@ -101,12 +100,13 @@ sub process_message {
 
     if ($exit_good == $exit_bad and $out_good eq $out_bad) {
       $self->tell($message, "On both starting points the exit code is $exit_bad and the output is identical as well");
-      return 'Output on both points: ' . decode_utf8($out_good); # will be gisted automatically if required
+      return "Output on both points: $out_good"; # will be gisted automatically if required
     }
     my $output_file = '';
     if ($exit_good == $exit_bad) {
       $self->tell($message, "Exit code is $exit_bad on both starting points, bisecting by using the output");
       (my $fh, $output_file) = tempfile(UNLINK => 1);
+      binmode $fh, ':encoding(UTF-8)';
       print $fh $out_good;
       close $fh;
     }
@@ -125,7 +125,7 @@ sub process_message {
     if ($init_status != 0) {
       chdir($oldDir);
       $self->tell($message, 'bisect log: ' . $self->upload({ 'query'  => $body,
-                                                             'result' => decode_utf8($init_output) }));
+                                                             'result' => $init_output }));
       return 'bisect init failure';
     }
     my ($bisect_output, $bisect_status);
@@ -142,7 +142,7 @@ sub process_message {
       }
     }
     $self->tell($message, 'bisect log: ' . $self->upload({ 'query'  => $body,
-                                                           'result' => decode_utf8("$init_output\n$bisect_output") }));
+                                                           'result' => "$init_output\n$bisect_output" }));
     if ($bisect_status != 0) {
       chdir($oldDir);
       return "'bisect run' failure";

committable.pl

@@ -25,7 +25,6 @@ package Committable;
 use parent 'Perl6IRCBotable';
 
 use Cwd qw(cwd abs_path);
-use Encode qw(decode_utf8);
 use IPC::Signal 'sig_name';
 
 use constant LIMIT => 300;
@@ -88,7 +87,6 @@ sub process_message {
         $out = 'No build for this commit';
       } else { # actually run the code
         ($out, my $exit, my $signal, my $time) = $self->get_output($self->BUILDS . "/$full_commit/bin/perl6", $filename);
-        $out = decode_utf8($out);
         $out .= " «exit code = $exit»" if ($exit != 0);
         if ($signal != 0) {
           my $signal_name = sig_name $signal;