In 0.1.1d there's no table.sort function. Intended?

You're right, it looks like table.sort isn't available in PICO-8 Lua, but you can implement something similar yourself. Here's an example:

function sort(t)
 for i=2,#t do
  local k,j=t[i],i-1
  while j>0 and t[j]>k do
   t[j+1]=t[j]
   j-=1
  end
  t[j+1]=k
 end
end

t={5,3,8,1,4}
sort(t)
for i=1,#t do
 print(t[i])
end

edit: Confirmed this works in Picotron as well.

table.sort is not available in Picotron

There are two alternatives that I know of, either using a custom sorting function:
abledbody shared their quicksort implementation here: https://www.lexaloffle.com/bbs/?tid=142305
And kimiyoribaka modified it so you can use it like table.sort in the comments here: https://www.lexaloffle.com/bbs/?tid=144442

Or:
Using userdata:sort
This can be a bit fiddly & might not be a good choice for every case - checkout demos/carpet.p64 for an example

Thanks for the links. I wonder why table.sort has been excluded, or if it's just not implemented yet.