* src/tgbaalgos/simulation.cc: Buid a tgba_digraph as the result of the
simulation.
* src/tgba/tgbagraph.hh (create_namer): New function.
* src/tgbatest/basimul.test: Add an additional test case that caused a
bug fixed in a previous patch.
* src/tgbatest/sim.test: Adjust.