Off-by-one when clearing stack slot after restart of a goto scope

[Karel Tuma <kat@...>]

Hi,

Not sure if this was reported.
This one was found via LuaJITs regression tests ported to Lua [1]:

do
  local k = 0
  local x
  ::foo::
  local y
  assert(not y)
  y = true
  k = k + 1
  if k < 2 then goto foo end
end

After removing the 'x' variable

do
  local k = 0
  ::foo::
  local y
  assert(not y)
  y = true
  k = k + 1
  if k < 2 then goto foo end
end

The test will pass. Hitting it on both 5.2 and 5.3.

[1] https://github.com/katlogic/lest