Expose symbols for darshan shutdown benchmarking in standard build
The darshan-test directory includes a test program (cp-shutdown-bench) that can be used to benchmark how long Darshan takes to aggregate, compress, and store log results at different scales. This benchmark cannot be used with a standard Darshan installation, however, because it relies on functions within the library that are normally commented out.
We should expose these timing hooks so that this particular aspect of Darshan can be more easily tested in production deployments.