branch wip-extensible-gexps created (now 78f7c26)

[Ludovic Courtès]

civodul pushed a change to branch wip-extensible-gexps
in repository guix.

        at  78f7c26   gexp: Separate "expanders" for origins and packages from 
the core.

This branch includes the following new commits:

       new  3f964ed   tests: Add an indirection for white-box testing.
       new  7201cca   gexp: Add <gexp-input>.
       new  23522f6   gexp: Export 'gexp-input' constructor.
       new  65fb39a   profiles: Use 'gexp-input' instead of two-element lists.
       new  58a543d   gexp: Remove special meaning of forms (PACKAGE OUTPUT) in 
ungexp.
       new  78f7c26   gexp: Separate "expanders" for origins and packages from 
the core.

The 6 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails.  The revisions
listed as "adds" were already present in the repository and have only
been added to this reference.