Add a "fork" of musl as //fusl.

fusl/arch/x86_64/bits/signal.h

Index: fusl/arch/x86_64/bits/signal.h
diff --git a/fusl/arch/x86_64/bits/signal.h b/fusl/arch/x86_64/bits/signal.h
new file mode 100644
index 0000000000000000000000000000000000000000..e3c314175c4e4fbcba6fae566c679e641716986f
--- /dev/null
+++ b/fusl/arch/x86_64/bits/signal.h
@@ -0,0 +1,130 @@
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+
+#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define MINSIGSTKSZ 2048
+#define SIGSTKSZ 8192
+#endif
+
+#ifdef _GNU_SOURCE
+#define REG_R8          0
+#define REG_R9          1
+#define REG_R10         2
+#define REG_R11         3
+#define REG_R12         4
+#define REG_R13         5
+#define REG_R14         6
+#define REG_R15         7
+#define REG_RDI         8
+#define REG_RSI         9
+#define REG_RBP         10
+#define REG_RBX         11
+#define REG_RDX         12
+#define REG_RAX         13
+#define REG_RCX         14
+#define REG_RSP         15
+#define REG_RIP         16
+#define REG_EFL         17
+#define REG_CSGSFS      18
+#define REG_ERR         19
+#define REG_TRAPNO      20
+#define REG_OLDMASK     21
+#define REG_CR2         22
+#endif
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+typedef long long greg_t, gregset_t[23];
+typedef struct _fpstate {
+	unsigned short cwd, swd, ftw, fop;
+	unsigned long long rip, rdp;
+	unsigned mxcsr, mxcr_mask;
+	struct {
+		unsigned short significand[4], exponent, padding[3];
+	} _st[8];
+	struct {
+		unsigned element[4];
+	} _xmm[16];
+	unsigned padding[24];
+} *fpregset_t;
+struct sigcontext {
+	unsigned long r8, r9, r10, r11, r12, r13, r14, r15;
+	unsigned long rdi, rsi, rbp, rbx, rdx, rax, rcx, rsp, rip, eflags;
+	unsigned short cs, gs, fs, __pad0;
+	unsigned long err, trapno, oldmask, cr2;
+	struct _fpstate *fpstate;
+	unsigned long __reserved1[8];
+};
+typedef struct {
+	gregset_t gregs;
+	fpregset_t fpregs;
+	unsigned long long __reserved1[8];
+} mcontext_t;
+#else
+typedef struct {
+	unsigned long __space[32];
+} mcontext_t;
+#endif
+
+struct sigaltstack {
+	void *ss_sp;
+	int ss_flags;
+	size_t ss_size;
+};
+
+typedef struct __ucontext {
+	unsigned long uc_flags;
+	struct __ucontext *uc_link;
+	stack_t uc_stack;
+	mcontext_t uc_mcontext;
+	sigset_t uc_sigmask;
+	unsigned long __fpregs_mem[64];
+} ucontext_t;
+
+#define SA_NOCLDSTOP  1
+#define SA_NOCLDWAIT  2
+#define SA_SIGINFO    4
+#define SA_ONSTACK    0x08000000
+#define SA_RESTART    0x10000000
+#define SA_NODEFER    0x40000000
+#define SA_RESETHAND  0x80000000
+#define SA_RESTORER   0x04000000
+
+#endif
+
+#define SIGHUP    1
+#define SIGINT    2
+#define SIGQUIT   3
+#define SIGILL    4
+#define SIGTRAP   5
+#define SIGABRT   6
+#define SIGIOT    SIGABRT
+#define SIGBUS    7
+#define SIGFPE    8
+#define SIGKILL   9
+#define SIGUSR1   10
+#define SIGSEGV   11
+#define SIGUSR2   12
+#define SIGPIPE   13
+#define SIGALRM   14
+#define SIGTERM   15
+#define SIGSTKFLT 16
+#define SIGCHLD   17
+#define SIGCONT   18
+#define SIGSTOP   19
+#define SIGTSTP   20
+#define SIGTTIN   21
+#define SIGTTOU   22
+#define SIGURG    23
+#define SIGXCPU   24
+#define SIGXFSZ   25
+#define SIGVTALRM 26
+#define SIGPROF   27
+#define SIGWINCH  28
+#define SIGIO     29
+#define SIGPOLL   29
+#define SIGPWR    30
+#define SIGSYS    31
+#define SIGUNUSED SIGSYS
+
+#define _NSIG 65
+