Make UCS_to_most.pl process encodings in sorted order

This just makes the progress output easier to follow.

Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/22016aa9-ca59-15c7-01df-f292cb558c4d@enterprisedb.com

src/backend/utils/mb/Unicode/UCS_to_most.pl

@@ -54,7 +54,8 @@ my %filename = (
 # make maps for all encodings if not specified
 my @charsets = (scalar(@ARGV) > 0) ? @ARGV : sort keys(%filename);
 
-foreach my $charset (@charsets)
+# the sort is just so that the output is easier to eyeball
+foreach my $charset (sort @charsets)
 {
 	my $mapping = &read_source($filename{$charset});