patch 8.0.0572: building the command table requires Perl

Problem:    Building the command table requires Perl.
Solution:   Use a Vim script solution. (Dominique Pelle, closes #1641)
diff --git a/src/Makefile b/src/Makefile
index 11f62f3..6283451 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1885,15 +1885,12 @@
 	-rm -rf autom4te.cache
 	-rm -f auto/config.status auto/config.cache
 
-# Run Perl to generate the Ex command lookup table.  This only needs to be run
-# when a command name has been added or changed.
-# NOTE: Only works when perl and vim executables are available
+# Run vim script to generate the Ex command lookup table.
+# This only needs to be run when a command name has been added or changed.
+# If this fails because you don't have Vim yet, first build and install Vim
+# without changes.
 cmdidxs: ex_cmds.h
-	if test X`perl -e "print 123"` = "X123"; then \
-	   vim ex_docmd.c -c '/Beginning.*create_cmdidxs/,/End.*create_cmdidxs/! perl create_cmdidxs.pl' -c wq; \
-	else \
-	   echo Cannot run Perl; \
-	fi
+	vim -u NONE -i NONE -X -S create_cmdidxs.vim
 
 # Re-execute this Makefile to include the new auto/config.mk produced by
 # configure Only used when typing "make" with a fresh auto/config.mk.