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/struct/ucontext-freebsd.internal.h

@@ -0,0 +1,102 @@
+#ifndef COSMOPOLITAN_LIBC_CALLS_STRUCT_UCONTEXT_FREEBSD_INTERNAL_H_
+#define COSMOPOLITAN_LIBC_CALLS_STRUCT_UCONTEXT_FREEBSD_INTERNAL_H_
+#include "libc/calls/struct/sigaction-freebsd.internal.h"
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+union sigval_freebsd {
+  int32_t sival_int;
+  void *sival_ptr;
+  int32_t sigval_int;
+  void *sigval_ptr;
+};
+
+struct siginfo_freebsd {
+  int32_t si_signo;
+  int32_t si_errno;
+  int32_t si_code;
+  int32_t si_pid;
+  uint32_t si_uid;
+  int32_t si_status;
+  void *si_addr;
+  union sigval_freebsd si_value;
+  union {
+    struct {
+      int32_t _trapno;
+    } _fault;
+    struct {
+      int32_t _timerid;
+      int32_t _overrun;
+    } _timer;
+    struct {
+      int32_t _mqd;
+    } _mesgq;
+    struct {
+      int64_t _band;
+    } _poll;
+    struct {
+      int64_t __spare1__;
+      int32_t __spare2__[7];
+    } __spare__;
+  } _reason;
+};
+
+struct stack_freebsd {
+  void *ss_sp;
+  uint64_t ss_size;
+  int32_t ss_flags;
+};
+
+struct mcontext_freebsd {
+  int64_t mc_onstack;
+  int64_t mc_rdi;
+  int64_t mc_rsi;
+  int64_t mc_rdx;
+  int64_t mc_rcx;
+  int64_t mc_r8;
+  int64_t mc_r9;
+  int64_t mc_rax;
+  int64_t mc_rbx;
+  int64_t mc_rbp;
+  int64_t mc_r10;
+  int64_t mc_r11;
+  int64_t mc_r12;
+  int64_t mc_r13;
+  int64_t mc_r14;
+  int64_t mc_r15;
+  uint32_t mc_trapno;
+  uint16_t mc_fs;
+  uint16_t mc_gs;
+  int64_t mc_addr;
+  uint32_t mc_flags;
+  uint16_t mc_es;
+  uint16_t mc_ds;
+  int64_t mc_err;
+  int64_t mc_rip;
+  int64_t mc_cs;
+  int64_t mc_rflags;
+  int64_t mc_rsp;
+  int64_t mc_ss;
+  int64_t mc_len;
+  int64_t mc_fpformat;
+  int64_t mc_ownedfp;
+  int64_t mc_fpstate[64];
+  int64_t mc_fsbase;
+  int64_t mc_gsbase;
+  int64_t mc_xfpustate;
+  int64_t mc_xfpustate_len;
+  int64_t mc_spare[4];
+};
+
+struct ucontext_freebsd {
+  struct sigset_freebsd uc_sigmask;
+  struct mcontext_freebsd uc_mcontext;
+  struct ucontext_freebsd *uc_link;
+  struct stack_freebsd uc_stack;
+  int32_t uc_flags;
+  int32_t __spare__[4];
+};
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_LIBC_CALLS_STRUCT_UCONTEXT_FREEBSD_INTERNAL_H_ */