Import C++ Standard Template Library

You can now use the hardest fastest and most dangerous language there is
with Cosmopolitan. So far about 75% of LLVM libcxx has been added. A few
breaking changes needed to be made to help this go smoothly.

- Rename nothrow to dontthrow
- Rename nodiscard to dontdiscard
- Add some libm functions, e.g. lgamma, nan, etc.
- Change intmax_t from int128 to int64 like everything else
- Introduce %jjd formatting directive for int128_t
- Introduce strtoi128(), strtou128(), etc.
- Rename bsrmax() to bsr128()

Some of the templates that should be working currently are std::vector,
std::string, std::map, std::set, std::deque, etc.

tool/hash/crctab.c

@@ -34,7 +34,7 @@ int main(int argc, char *argv[]) {
     exit(1);
   }
   static uint32_t tab[256];
-  crc32init(tab, strtoimax(argv[1], NULL, 0));
+  crc32init(tab, strtol(argv[1], NULL, 0));
   for (unsigned i = 0; i < ARRAYLEN(tab); ++i) {
     if (i > 0) {
       printf(",");