Perf work

[arcanis]

What's the problem this PR addresses?

This diff implements a couple of small performance improvements.

How did you fix it?

• Removed nodeUtils.builtinModules (use module.builtinModules)
• Optimized some ppath functions on non-win32 platforms
• Removed toFilename (just cast to Filename if needed)
• The yarnPath same-file check now uses inodes on non-win32 platforms
• Hoisted a couple of regexps to avoid re-instantiations

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
before	236.5 ± 2.7	233.2	241.0	1.06 ± 0.02
after	222.7 ± 3.2	219.6	230.7	1.00

Checklist

• I have read the Contributing Guide.

• I have set the packages that need to be released for my changes to be effective.

• I will check that all automated PR checks pass before the PR gets reviewed.

[merceyz]

This wont catch cases where the file content is the same but the inode isn't, for example with Corepack and yarnPath the inode (most likely) wont be the same but the content probably is.

[arcanis]

Having exactly the same version in Corepack and yarnPath (considering that V4 use Corepack without yarnPath when possible) seems in theory unlikely enough that it's tolerable

Perhaps a problem though is that existing projects will have a hard time noticing that they should remove yarnPath from their configuration and fully migrate to Corepack... 🤔

[arcanis]

I'll make a separate PR to add a warning when yarnPath is detected when it could be Corepack