Make improvements for Actually Portable Emacs

- Get SIGWINCH working again on the New Technology
- Correctly handle O_NOFOLLOW in open() on Windows
- Implement synthetic umask() functionality on Windows
- Do a better job managing file execute access on Windows
- Fill in `st_uid` and `st_gid` with username hash on Windows
- Munge UNICODE control pictures into control codes on Windows
- Do a better job ensuring Windows console settings are restored
- Introduce KPRINTF_LOG environment variable to log kprintf to a file

libc/runtime/exit.c

@@ -16,11 +16,9 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/dce.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
 #include "libc/runtime/internal.h"
-#include "libc/runtime/runtime.h"
 
 /**
  * Exits process with grace.
@@ -45,9 +43,5 @@ wontreturn void exit(int exitcode) {
   for (p = __fini_array_end; p > __fini_array_start;) {
     ((void (*)(void))(*--p))();
   }
-#if SupportsWindows()
-  _Exitr(exitcode);
-#else
   _Exit(exitcode);
-#endif
 }