We still don't have any PSL-specific reductions, but at least
the LTL reduction now appear to work on PSL formulas.

* src/ltlvisit/basicreduce.cc (basic_reduce_visitor): Fix the
call to std::copy to handle Concat, Fusion, and AndNLM.
* src/ltlvisit/reduce.cc (reduce_visitor): Fix handling
of UConcat, EConcat, and EConcatMarked.
* src/tgbatest/randpsl.test: Activate reductions.
* src/ltltest/reducpsl.test: New file.
* src/ltltest/Makefile.am (TESTS): Add it.