Optimize forwarded calls

[marcandre]

Fixes [#312]

@Earlopain do you have a minute to review the PR? 🙏

[bbatsov]

Did you manage to get the same 3% speedup?

[Earlopain]

This looks fine to me, benchmarking confirms:

Current:
$ hyperfine -w 3 -r 20 "bundle exec rubocop Rakefile" 
Benchmark 1: bundle exec rubocop Rakefile
  Time (mean ± σ):      2.907 s ±  0.133 s    [User: 2.458 s, System: 0.242 s]
  Range (min … max):    2.802 s …  3.408 s    20 runs

PR:  
$ hyperfine -w 3 -r 20 "bundle exec rubocop Rakefile" 
Benchmark 1: bundle exec rubocop Rakefile
  Time (mean ± σ):      2.695 s ±  0.084 s    [User: 2.297 s, System: 0.229 s]
  Range (min … max):    2.596 s …  2.918 s    20 runs

This is with the changes from rubocop itself already applied. It's a weaker machine than the other benchmark so numbers are different and apparently matter even more since it's about 7% just with this change. I haven't tested but it's probably that file system operations are similarly fast while the CPU is not (or something similar to that effect).

Either way, still achives the original goal. Thanks!

[marcandre]

Thanks!

Released as 1.32.2

I'd recommend using that in rubocop too.