returning nil function call counts causes return count error

[lewis6991]

local function fnil()
  return
end

local f --- @type fun(c: fun())
f(function()
  return fnil()
end)

fnil doesn't return anything, so I don't think this message is correct.

[lewis6991]

Can verify this is indeed wrong with:

local function f0()
  return
end

local function f1()
  return nil
end

local f --- @type fun(c: fun())

function f(c)
  local function count_rets(...)
    print(select('#', ...))
  end
  count_rets(c())
end

f(function()
  return f0()
end)
-- prints 0

f(function()
  return f1()
end)
-- prints 1

[lewis6991]

This is also wrong:

--- @return nil
local function f1()
  return nil
end