use "len(buf)-1" to access final slice index to eliminate a few more boundary checks

[NyaaaWhatsUpDoc]

Also learnt in the process that when it comes to boundary checking Go doesn't seem to trust its own allocated slice length (though I'm assuming this wasn't a choice). So any slice allocated with a variable length, even if you know it's at least literal x because the length is x+$uintVariable, it still performs boundary checks on all the slice indices up to x-1 unless you put a manual check directly after the slice allocation. There were a few cases of these that could be added here, but given it's an almost pointlessly small optimization that frankly has a weird "code smell" (given you're checking the length of a slice directly after allocating it), I didn't bother including them. Though I might see if there's an issue open for it on the Go project.

[ncruces]

Yeah, I tried a couple of things on this file, couldn't remove the bulk of the checks, and just gave up.

But nice to see you could remove a couple.