Korn: add __VERIFIER.c for counterexample checking
Korn: add __VERIFIER.c for counterexample checking

ultimate-pa/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec,ultimate-pa/benchexec,sosy-lab/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec,sosy-lab/benchexec,dbeyer/benchexec,dbeyer/benchexec,dbeyer/benchexec,sosy-lab/benchexec,sosy-lab/benchexec,ultimate-pa/benchexec