patch 8.0.0504: looking up an Ex command is a bit slow

Problem:    Looking up an Ex command is a bit slow.
Solution:   Instead of just using the first letter, also use the second letter
            to skip ahead in the list of commands. Generate the table with a
            Perl script. (Dominique Pelle, closes #1589)
diff --git a/Filelist b/Filelist
index 72a1f96..f67b059 100644
--- a/Filelist
+++ b/Filelist
@@ -215,6 +215,7 @@
 		src/config.mk.in \
 		src/configure \
 		src/configure.ac \
+		src/create_cmdidxs.pl \
 		src/gui_at_fs.c \
 		src/gui_at_sb.c \
 		src/gui_at_sb.h \