Improve synchronization

- Fix bugs in kDos2Errno definition
- malloc() should now be thread safe
- Fix bug in rollup.com header generator
- Fix open(O_APPEND) on the New Technology
- Fix select() on the New Technology and test it
- Work towards refactoring i/o for thread safety
- Socket reads and writes on NT now poll for signals
- Work towards i/o completion ports on the New Technology
- Make read() and write() intermittently check for signals
- Blinkenlights keyboard i/o so much better on NT w/ poll()
- You can now poll() files and sockets at the same time on NT
- Fix bug in appendr() that manifests with dlmalloc footers off

libc/calls/raise.c

@@ -23,6 +23,7 @@
 #include "libc/calls/strace.internal.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/nt/console.h"
+#include "libc/nt/errors.h"
 #include "libc/nt/process.h"
 #include "libc/nt/runtime.h"
 #include "libc/nt/synchronization.h"
@@ -65,7 +66,9 @@ int raise(int sig) {
       //      doesn't make any sense and it's so evil.
       if (GenerateConsoleCtrlEvent(event, 0)) {
         // XXX: we shouldn't need to sleep here ctrl-c is evil on nt
-        SleepEx(100, false);
+        if (SleepEx(100, true) == kNtWaitIoCompletion) {
+          STRACE("IOCP TRIGGERED EINTR");
+        }
         __sig_check(false);
         rc = 0;
       } else {