[build] Split stdlib to it's own opam package.

We introduce a new package structure for Coq:

- `coq-core`: Coq's OCaml tools code and plugins
- `coq-stdlib`: Coq's stdlib [.vo files]
- `coq`: meta-package that pulls `coq-{core,stdlib}`

This has several advantages, in particular it allows to install Coq
without the stdlib which is useful in several scenarios, it also open
the door towards a versioning of the stdlib at the package level.

The main user-visible change is that Coq's ML development files now
live in `$lib/coq-core`, for compatibility in the regular build we
install a symlink and support both setups for a while.

Note that plugin developers and even `coq_makefile` should actually
rely on `ocamlfind` to locate Coq's OCaml libs as to be more robust.

There is a transient state where we actually look for both
`$coqlib/plugins` and `$coqlib/../coq-core/plugins` as to support
the non-ocamlfind plus custom variables.

This will be much improved once #13617 is merged (which requires this
PR first), then, we will introduce a `coq.boot` library so finally
`coqdep`, `coqchk`, etc... can share the same path setup code.

IMHO the plan should work fine.

1 files changed, 4 insertions, 4 deletions

diff --git a/Makefile.make b/Makefile.make
index 5e45e71c8c..9f0e06dffc 100644
--- a/Makefile.make
+++ b/Makefile.make
@@ -187,10 +187,10 @@ Makefile $(wildcard Makefile.*) config/Makefile : ;
 ###########################################################################
 # OCaml dev files
 ###########################################################################
-camldevfiles: $(MERLINFILES) META.coq
+camldevfiles: $(MERLINFILES) META.coq-core
 
 # prevent submake dependency
-META.coq.in $(MERLININFILES): ;
+META.coq-core.in $(MERLININFILES): ;
 
 .merlin: .merlin.in
 	cp -a "$<" "$@"
@@ -198,7 +198,7 @@ META.coq.in $(MERLININFILES): ;
 %/.merlin: %/.merlin.in
 	cp -a "$<" "$@"
 
-META.coq: META.coq.in
+META.coq-core: META.coq-core.in
 	cp -a "$<" "$@"
 
 ###########################################################################
@@ -222,7 +222,7 @@ cruftclean: mlgclean
 	rm -f gmon.out core
 
 camldevfilesclean:
-	rm -f $(MERLINFILES) META.coq
+	rm -f $(MERLINFILES) META.coq-core
 
 indepclean:
 	rm -f $(GENFILES)