Improve locks and signals

- Introduce fast spinlock API
- Double rand64() perf w/ spinlock
- Improve raise() on New Technology
- Support gettid() across platforms
- Implement SA_NODEFER on New Technology
- Move the lock intrinsics into LIBC_INTRIN
- Make SIGTRAP recoverable on New Technology
- Block SIGCHLD in wait4() on New Technology
- Add threading prototypes for XNU and FreeBSD
- Rewrite abort() fixing its minor bugs on XNU/NT
- Shave down a lot of the content in libc/bits/bits.h
- Let signal handlers modify CPU registers on New Technology

libc/calls/write-nt.c

@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/calls/internal.h"
+#include "libc/calls/sig.internal.h"
 #include "libc/calls/strace.internal.h"
 #include "libc/calls/struct/iovec.h"
 #include "libc/calls/struct/siginfo.h"
@@ -29,22 +30,10 @@
 #include "libc/nt/struct/overlapped.h"
 #include "libc/runtime/internal.h"
 #include "libc/str/str.h"
+#include "libc/sysv/consts/sicode.h"
 #include "libc/sysv/consts/sig.h"
 #include "libc/sysv/errfuns.h"
 
-static textwindows ssize_t sys_write_nt_epipe(int fd) {
-  siginfo_t info;
-  STRACE("WriteFile(%d:%p) → %m", fd, g_fds.p[fd].handle);
-  if (!__sighandrvas[SIGPIPE]) {
-    __restorewintty();
-    _Exit(128 + SIGPIPE);
-  } else if (__sighandrvas[SIGPIPE] >= kSigactionMinRva) {
-    bzero(&info, sizeof(info));
-    ((sigaction_f)(_base + __sighandrvas[SIGPIPE]))(SIGPIPE, &info, 0);
-  }
-  return epipe();
-}
-
 static textwindows ssize_t sys_write_nt_impl(int fd, void *data, size_t size,
                                              ssize_t offset) {
   uint32_t sent;
@@ -53,7 +42,8 @@ static textwindows ssize_t sys_write_nt_impl(int fd, void *data, size_t size,
                 _offset2overlap(offset, &overlap))) {
     return sent;
   } else if (GetLastError() == kNtErrorBrokenPipe) {
-    return sys_write_nt_epipe(fd);
+    __sig_raise(SIGPIPE, SI_KERNEL);
+    return epipe();
   } else {
     return __winerr();
   }