Manage OCamlfind invocations.
The different invocation modes. Direct is the expanded
command-line, without any mention of `ocamlfind'
anymore. Indirect return the `ocamlfind' invocation to run to
get the right command-line, and Makefile is the same as
Indirect, but quoted inside a $(shell ...) string.
ocamlfind_query ~direct ?predicates ?format packages is the
result of executing ocamlfind query with the given
parameters. If direct is set, call the `ocamlfind' commands
directly. Otherwise, return the ocamlfind to run to get the
expected result.
Resolve command-line arguments for ocamlfind packages. Same as
As_resolver.maker but without the ~pkgs argument.