c/luainternals: fixed compilation for LJ2
c/luainternals: fixed compilation for LJ2

It does not have LUAI_BITSINT defined.
Assuming maximum value that is possible in Lua 5.1.

agladysh/luatexts,agladysh/luatexts,agladysh/luatexts,agladysh/luatexts,agladysh/luatexts