reduce readFileSync syscall count

[littledivy]

https://x.com/justjs14/status/1791963104881844360

Repro: https://gist.github.com/billywhizz/1d6fee4d3aea1030324a7a93de444d31

[sigmaSd]

Its probably due to permissions check, I think in the case of read when comparing paths deno need to canonicalize and normalize the paths, to know its allowed or not

Maybe absolute flags (as in --allow-read instead of --allow-read=path, etc) should not suffer the sandbox performance hit, since they can work in theory with just an extra boolean check and more importantly with no extra syscalls

[littledivy]

It's a regression from #23208

This getcwd code path should never reach with --allow-all and generic --allow-read https://github.com/denoland/deno/blob/fabd9a214b278bb119818187de66121c5f91b751/ext/fs/std_fs.rs#L904-L905