This improves the load time of most brew commands. For an example of
one of the simplest commands this speeds up:
Without Bootsnap:
```
$ hyperfine 'git checkout master; brew help' 'git checkout optimise_requires; brew help'
Benchmark 1: git checkout master; brew help
Time (mean ± σ): 525.0 ms ± 35.8 ms [User: 229.9 ms, System: 113.1 ms]
Range (min … max): 465.3 ms … 576.6 ms 10 runs
Benchmark 2: git checkout optimise_requires; brew help
Time (mean ± σ): 383.3 ms ± 25.1 ms [User: 133.0 ms, System: 72.1 ms]
Range (min … max): 353.0 ms … 443.6 ms 10 runs
Summary
git checkout optimise_requires; brew help ran
1.37 ± 0.13 times faster than git checkout master; brew help
```
With Bootsnap:
```
$ hyperfine 'git checkout master; brew help' 'git checkout optimise_requires; brew help'
Benchmark 1: git checkout master; brew help
Time (mean ± σ): 386.0 ms ± 30.9 ms [User: 130.2 ms, System: 93.8 ms]
Range (min … max): 359.5 ms … 469.3 ms 10 runs
Benchmark 2: git checkout optimise_requires; brew help
Time (mean ± σ): 330.2 ms ± 32.4 ms [User: 93.4 ms, System: 73.0 ms]
Range (min … max): 302.9 ms … 413.9 ms 10 runs
Summary
git checkout optimise_requires; brew help ran
1.17 ± 0.15 times faster than git checkout master; brew help
```
- Sort of. It's not via Parlour, because I read the docs and all it says
about dynamically generating things is "of course it's better to do
that", no examples. I tried my best, but Bo's work on `attr.rb` was
mind-boggling.
- Instead, let's add a simple but functional generator script that I
actually understand, as an alternative to maintaining these RBI files
for dynamic methods manually, so that we can get rid of some use of
`srb rbi hidden-definitions` since that's deprecated.
- TODO: Run this script as part of `brew typecheck --update` so it gets
updated with all the other RBI files periodically.
- Follow up to PR 14651.
When stdin is not a tty then the message `stty: stdin isn't a terminal`
will be produced. Silence this message and fall back to `tput` when it
fails and default to 80 if we get no results at all.
Follow-up from #2714.
