Avoid installing META files for  camlp4, labltk, and num.
Those are provided by their respective packages now.

Index: findlib-1.8.0/configure
===================================================================
--- configure.orig	2018-10-10 13:17:35.000000000 -0400
+++ configure	2018-10-10 13:17:38.000000000 -0400
@@ -581,7 +581,7 @@
 
 # Generate the META files now.
 
-l="$ldbm dynlink $lgraphics $lnum str threads unix stdlib bigarray ocamldoc $llabltk $lcamlp4 $lobuild $lcomplibs $lbytes $lspacetime"
+l="$ldbm dynlink $lgraphics str threads unix stdlib bigarray ocamldoc $lobuild $lcomplibs $lbytes $lspacetime"
 
 for dir in site-lib-src/*; do
     # We do not really know if $dir is a directory.