Improve performance of post_process()

[etiennebacher]

The benchmarks below use the package cross:

cross::bench_versions(pkgs = c("gaborcsardi/cyclocomp", "etiennebacher/cyclocomp@speedup"), {
  bench::mark(cyclocomp::cyclocomp_package("polars"))
})
#> # A tibble: 2 × 7
#>   pkg                       expression   min median `itr/sec` mem_alloc `gc/sec`
#>   <chr>                     <bch:expr> <bch> <bch:>     <dbl> <bch:byt>    <dbl>
#> 1 gaborcsardi/cyclocomp     "cyclocom… 5.78s  5.78s     0.173     661MB     7.97
#> 2 etiennebacher/cyclocomp@… "cyclocom… 2.97s  2.97s     0.337     483MB    13.1


cross::bench_versions(pkgs = c("gaborcsardi/cyclocomp", "etiennebacher/cyclocomp@speedup"), {
  bench::mark(cyclocomp::cyclocomp_package("dplyr"))
})
#> # A tibble: 2 × 7
#>   pkg                       expression   min median `itr/sec` mem_alloc `gc/sec`
#>   <chr>                     <bch:expr> <bch> <bch:>     <dbl> <bch:byt>    <dbl>
#> 1 gaborcsardi/cyclocomp     "cyclocom…  3.5s   3.5s     0.286     341MB     7.71
#> 2 etiennebacher/cyclocomp@… "cyclocom… 2.73s  2.73s     0.367     192MB    12.1


cross::bench_versions(pkgs = c("gaborcsardi/cyclocomp", "etiennebacher/cyclocomp@speedup"), {
  bench::mark(cyclocomp::cyclocomp_package("lintr"))
})
#> # A tibble: 2 × 7
#>   pkg                       expression   min median `itr/sec` mem_alloc `gc/sec`
#>   <chr>                     <bch:expr> <bch> <bch:>     <dbl> <bch:byt>    <dbl>
#> 1 gaborcsardi/cyclocomp     "cyclocom… 4.76s  4.76s     0.210     833MB     5.88
#> 2 etiennebacher/cyclocomp@… "cyclocom… 1.75s  1.75s     0.573     183MB    27.5