Minor Optimisations

[MaxC25]

I would have done a pull request had I been bothered to do a fork, but here are my things:
all instances of math.floor(n/2), such as the one in scripts/benchmark_check.ts should become n>>1, mathematically identical but faster as JS can not handle any iterable longer than 2^32-1 words, and the line,
return sorted.length % 2 === 0 ? (sorted[mid - 1]! + sorted[mid]!) / 2 : sorted[mid]!
could become
return sorted.length & 1 ? sorted[mid]! : (sorted[mid - 1]! + sorted[mid]!) / 2
which is equivilant but probably slightly faster, and if you don't like the re-ordering, you can do
return ~(sorted.length & 1) ? (sorted[mid - 1]! + sorted[mid]!) / 2 : sorted[mid]!

and in scripts/build-demo-site.ts

if (result.exitCode !== 0) {
  process.exit(result.exitCode)
}

could become

if (result.exitCode) {
  process.exit(result.exitCode)
}

, which I think is neater, with no performance disadvantages that I know of, and this can be generalised to replace all if(num!=0) with if(num)

Also, on line 330, process.exitCode = 1 maybe could become process.exitcode = 1&0xFF to make it obvious to the browser that this is not a float but an integer that fits in 8 bits, but take this with a grain of salt as this does feel a bit pointless and contradicts my previous point about neatness.

The same goes for adding |0 after integer declarations and simple reassignments e.g x=y to make it obvious to a bad compiler that it's an integer to maybe speed it up, but again, this feels pointless and probably is, alongside being not particularly elegant so I would not recommend it, but you can consider it.