Add []-> and <>->.

* src/ltlast/binop.hh, src/ltlast/binop.cc (EConcat, UConcat):
Add these new operators.
* src/ltlparse/ltlparse.yy, src/ltlparse/ltlscan.ll: Parse
these new operators.
* src/ltlvisit/simpfg.cc, src/ltlvisit/syntimpl.cc,
src/ltlvisit/tostring.cc, src/ltlvisit/basicreduce.cc,
src/ltlvisit/consterm.cc, src/ltlvisit/lunabbrev.cc,
src/ltlvisit/nenoform.cc, src/ltlvisit/reduce.cc
src/tgba/formula2bdd.cc, src/tgbaalgos/eltl2tgba_lacim.cc,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_lacim.cc: Add these new operators into the
switches.

src/tgbaalgos/eltl2tgba_lacim.cc

@@ -129,6 +129,8 @@ namespace spot
 	  case binop::R:
 	  case binop::W:
 	  case binop::M:
+	  case binop::UConcat:
+	  case binop::EConcat:
 	    assert(!"unsupported operator");
 	  }
 	/* Unreachable code.  */

src/tgbaalgos/ltl2taa.cc

@@ -247,6 +247,9 @@ namespace spot
 	case binop::Implies:
 	case binop::Equiv:
 	  assert(0); // TBD
+	case binop::UConcat:
+	case binop::EConcat:
+	  assert(!"unsupported operator");
 	}
 	/* Unreachable code.  */
 	assert(0);

src/tgbaalgos/ltl2tgba_fm.cc

@@ -418,6 +418,10 @@ namespace spot
 	      res_ = (f1 & f2) | (bdd_ithvar(a) & f2 & bdd_ithvar(x));
 	      return;
 	    }
+	  case binop::UConcat:
+	  case binop::EConcat:
+	    assert(!"unsupported operator");
+	    break;
 	  }
 	/* Unreachable code.  */
 	assert(0);
@@ -527,6 +531,10 @@ namespace spot
 	  case binop::W:
 	    res_ = true;
 	    return;
+	  case binop::UConcat:
+	  case binop::EConcat:
+	    node->second()->accept(*this);
+	    return;
 	  }
 	/* Unreachable code.  */
 	assert(0);

src/tgbaalgos/ltl2tgba_lacim.cc

@@ -220,6 +220,10 @@ namespace spot
 	      res_ = now;
 	      return;
 	    }
+	  case binop::UConcat:
+	  case binop::EConcat:
+	    assert(!"unsupported operator");
+	    break;
 	  }
 	/* Unreachable code.  */
 	assert(0);