tests/test-fuzz-targets.t

py3: add b'' prefixes in test-abort-checkin.t

# skip-blame because we just added a b'' prefix.

#require clang-libfuzzer test-repo
  $ cd $TESTDIR/../contrib/fuzz
  $ make
Just run the fuzzer for five seconds to verify it works at all.
  $ ./bdiff -max_total_time 5