[make] Fix build in split num configuration.

It seems that recent fixes using ocamlbuild to locate num missed to
switch in some binaries. This is needed to solve problems like the
one in this issue: ocaml/opam-repository#11316

Makefile.build

@@ -530,7 +530,7 @@ CSDPCERTCMO:=lib/clib.cma $(addprefix plugins/micromega/, \
 
 $(CSDPCERT): $(call bestobj, $(CSDPCERTCMO))
 	$(SHOW)'OCAMLBEST -o $@'
-	$(HIDE)$(call bestocaml,,nums unix)
+	$(HIDE)$(call bestocaml,-linkpkg -package num -package unix,)
 
 ###########################################################################
 # tests

tools/coqmktop.ml

@@ -108,7 +108,7 @@ let incl_all_subdirs dir opts =
 
 (** OCaml + CamlpX libraries *)
 
-let ocaml_libs = ["str.cma";"unix.cma";"nums.cma";"dynlink.cma";"threads.cma"]
+let ocaml_libs = ["str.cma";"unix.cma";"dynlink.cma";"threads.cma"]
 let camlp4_libs = ["gramlib.cma"]
 let libobjs = ocaml_libs @ camlp4_libs
 
@@ -289,6 +289,7 @@ let main () =
       List.filter ((<>) "") (split_on_char ' ' Coq_config.caml_flags) in
     let args =
       coq_camlflags @ "-linkall" :: "-w" :: "-31" :: flags @ copts @ options @
+      ["-linkpkg"; "-package"; "num"] @
       (std_includes basedir) @ tolink @ [ main_file ] @ topstart
     in
     if !echo then begin