We do that because the declaration of this type, which is local to
src/tgba/tgbasafracomplement.cc has a member in an anonymous
namespace, and some versions of g++-4.2 issue a very annoying
warning about this legitimate code. See Bug 29365 on GCC's
Bugzilla. Report by Silien Hong <silien.hong@lip6.fr>.
* src/tgba/tgbasafracomplement.hh (safra_tree_automaton): Do not
forward declare.
(tgba_safra_complement): Use void* instead of
safra_tree_automaton*.
* src/tgba/tgbasafracomplement.cc: static_cast void* to
safra_tree_automaton* anywhere needed.
* src/tgbatest/ltl2tgba.cc (main): Call scc_filter() before the
degeneralization, because it might remove useless acceptance
conditions. I realized this while looking at experiments from
Rüdiger Ehlers.
