Fix parallel build failure In parallel builds this "bison && mv" ran twice in parallel, FTBFS if this resulted in the following sequence: bison -t -o gecode/flatzinc/parser.tab.cpp -d gecode/flatzinc/parser.yxx bison -t -o gecode/flatzinc/parser.tab.cpp -d gecode/flatzinc/parser.yxx mv gecode/flatzinc/parser.tab.hpp gecode/flatzinc/parser.tab.hh mv gecode/flatzinc/parser.tab.hpp gecode/flatzinc/parser.tab.hh Running it only once fixes the problem.
