exception based error handling for SMT2 files

Author: Daniel Kroening

regression/smt2_solver/function-applications/function-application2.desc

@@ -1,7 +1,7 @@
 CORE
 function-application2.smt2
 
-^EXIT=134$
+^EXIT=20$
 ^SIGNAL=0$
 ^line 5: type mismatch in function definition: expected `\(_ BitVec 16\)' but got `\(_ BitVec 8\)'$
 --