gnatgcc moving from gnat to gnat-x.y

[Nicolas Boulenguez <nicolas.boulenguez@free.fr>]

In-Reply-To=<[🔎] 87eh1ub11m.fsf@ludovic-brenta.org>

I have uploaded to unstable:
- gnat 4.6.1  (Arch: all)
  Depends: gnat-4.6 (>= 4.6.4-2) to provide the gnatgcc symbolic link.
- gnat-4.6 4.6.4-2  (Arch: any)
  Breaks&Replaces: gnat (<< 4.6.1) to avoid a file conflict about gnatgcc.

This creates a circular build-dependency, because
- gnat-4.6 Build-Depends: gnat (>= 4.1) (via GNAT_BUILD_DEP in rules.conf).

Even with the comments in rules.conf, I wonder why gnat-4.6 depends on
gnat, and would appreciate any hint to break this circular dependency.