Include CONFIG_ARGS in Metadata

[JeffersGlass]

It would be useful to have the information from the CONFIG_ARGS variable in the metadata for a benchmark file.

The use case is: determining whether two benchmarks were built from the same Python commit and built with the same options (specifically with regards to the new JIT and PGO).

For more context - I am experimenting with paralleling pyperformance across several machines, and for efficiency I am caching several builds of Python on each machine. In order to generate useful comparison data between many different benchmark files, it's useful to extract the commit, JIT and PGO status from the benchmark files themselves.

If there's a better way to determine that data, I'd be open to that.

I have a branch which adds in this info, if it would be useful to submit a PR.

[vstinner]

Do you want to propose a PR for that?

[JeffersGlass]

Sure! I've opened #180, which is linked to this issue.

[vstinner]

Fixed by 9a99cbe