Fix incorrect use of global in FFI code. Locallize some globals from standard library in FFI code.

src/pre_generated-zmq.nobj.c

@@ -705,7 +705,12 @@ static int nobj_try_loading_ffi(lua_State *L, const char *ffi_mod_name,
 
 
 
-static const char zmq_ffi_lua_code[] = "-- try loading luajit's ffi\n"
+static const char zmq_ffi_lua_code[] = "local error = error\n"
+"local type = type\n"
+"local tonumber = tonumber\n"
+"local tostring = tostring\n"
+"\n"
+"-- try loading luajit's ffi\n"
 "local stat, ffi=pcall(require,\"ffi\")\n"
 "if not stat then\n"
 "	return\n"
@@ -792,7 +797,7 @@ static const char zmq_ffi_lua_code[] = "-- try loading luajit's ffi\n"
 "	end\n"
 "\n"
 "	-- create new userdata\n"
-"	ud_obj = udata_new(ffi.sizeof\"obj_udata\", type_mt)\n"
+"	local ud_obj = udata_new(ffi.sizeof\"obj_udata\", type_mt)\n"
 "	local ud = ffi.cast(\"obj_udata *\", ud_obj)\n"
 "	-- init. object\n"
 "	ud.obj = obj\n"
@@ -865,7 +870,7 @@ static const char zmq_ffi_lua_code[] = "-- try loading luajit's ffi\n"
 "	if c_obj == nil then return end\n"
 "\n"
 "	-- create new userdata\n"
-"	ud_obj = udata_new(size, type_mt)\n"
+"	local ud_obj = udata_new(size, type_mt)\n"
 "	local cdata = ffi.cast(\"void *\", ud_obj)\n"
 "	-- init. object\n"
 "	ffi.copy(cdata, c_obj, size)\n"