Cosmopolitan currently doesn't support threads and it doesn't do
anything fancy in longjmp/setjmp so this change was simple to do
- localeconv
- _setjmp (same as setjmp)
- _longjmp (same as longjmp)
- strcoll (same as strcmp)
- flockfile (does nothing)
- funlockfile (does nothing)
- ftrylockfile (does nothing)
See #61
