[PATCH 0/3] Add xdot and update yosys

[Theodoros Foradis]

Hello guix,

This patch adds xdot, a viewer for graphviz graphs, and adds support for
it in yosys(it was a TODO item).

Functionality can be tested following the examples in this webpage:
http://www.clifford.at/yosys/screenshots.html
The diagrams at each step, can be previewed with xdot, issuing the
command 'show counter'.

Also, yosys is updated to the latest release, 0.7.

Regards,
-- 
Theodoros Foradis