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/getconsolectrlevent.internal.h

@@ -0,0 +1,21 @@
+#ifndef COSMOPOLITAN_LIBC_CALLS_GETCONSOLECTRLEVENT_H_
+#define COSMOPOLITAN_LIBC_CALLS_GETCONSOLECTRLEVENT_H_
+#include "libc/nt/enum/ctrlevent.h"
+#include "libc/sysv/consts/sig.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+static inline int GetConsoleCtrlEvent(int sig) {
+  switch (sig) {
+    case SIGINT:
+      return kNtCtrlCEvent;
+    case SIGQUIT:
+      return kNtCtrlBreakEvent;
+    default:
+      return -1;
+  }
+}
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_CALLS_GETCONSOLECTRLEVENT_H_ */