Currently, libFuzzer will exit with an error message if a non-existent
directory is provided for any of the appropriate arguments. For cases
where libFuzzer is used in a specialized embedded environment, it would
be much easier to have libFuzzer create the directories for the user.
This patch accommodates for this scenario by allowing the user to provide
the argument -create_missing_dirs=1 which makes libFuzzer attempt to
create the artifact_prefix, exact_artifact_path,
features_dir and/or corpus directory if they don't already exist rather
than throw an error and exit.
clang-tidy: warning: invalid case style for function 'ValidateDirectoryExists' [readability-identifier-naming]
not useful