fix for strict.lua over stripped bytecode

strict.lua

@@ -5,6 +5,8 @@
 -- (even assigning nil will do) in a main chunk before being used
 -- anywhere or assigned to inside a function.
 --
+-- modified for better compatibility with LuaJIT, see:
+-- http://www.freelists.org/post/luajit/strictlua-with-stripped-bytecode
 
 local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget
 
@@ -16,15 +18,10 @@ end
 
 mt.__declared = {}
 
-local function what ()
-  local d = getinfo(3, "S")
-  return d and d.what or "C"
-end
-
 mt.__newindex = function (t, n, v)
   if not mt.__declared[n] then
-    local w = what()
-    if w ~= "main" and w ~= "C" then
+    local info = getinfo(2, "S")
+    if info and info.linedefined > 0 then
       error("assign to undeclared variable '"..n.."'", 2)
     end
     mt.__declared[n] = true
@@ -33,8 +30,11 @@ mt.__newindex = function (t, n, v)
 end
 
 mt.__index = function (t, n)
-  if not mt.__declared[n] and what() ~= "C" then
-    error("variable '"..n.."' is not declared", 2)
+  if not mt.__declared[n] then
+    local info = getinfo(2, "S")
+    if info and info.linedefined > 0 then
+      error("variable '"..n.."' is not declared", 2)
+    end
   end
   return rawget(t, n)
 end