Function luajit2_sys::lua_upvaluejoin

pub unsafe extern "C" fn lua_upvaluejoin(
    L: *mut lua_State, 
    idx1: c_int, 
    n1: c_int, 
    idx2: c_int, 
    n2: c_int
)

https://www.lua.org/manual/5.1/manual.html#lua_upvaluejoin