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

fusl/arch/aarch64/bits/signal.h

Index: fusl/arch/aarch64/bits/signal.h
diff --git a/fusl/arch/aarch64/bits/signal.h b/fusl/arch/aarch64/bits/signal.h
new file mode 100644
index 0000000000000000000000000000000000000000..ef07cc9f0cda22e8d0627a781c3032da4c93da2d
--- /dev/null
+++ b/fusl/arch/aarch64/bits/signal.h
@@ -0,0 +1,108 @@
+#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 6144
+#define SIGSTKSZ 12288
+#endif
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+typedef unsigned long greg_t;
+typedef unsigned long gregset_t[34];
+
+typedef struct {
+	long double vregs[32];
+	unsigned int fpsr;
+	unsigned int fpcr;
+} fpregset_t;
+typedef struct sigcontext
+{
+	unsigned long fault_address;
+	unsigned long regs[31];
+	unsigned long sp, pc, pstate;
+	long double __reserved[256];
+} mcontext_t;
+
+#define FPSIMD_MAGIC 0x46508001
+#define ESR_MAGIC 0x45535201
+struct _aarch64_ctx {
+	unsigned int magic;
+	unsigned int size;
+};
+struct fpsimd_context {
+	struct _aarch64_ctx head;
+	unsigned int fpsr;
+	unsigned int fpcr;
+	long double vregs[32];
+};
+struct esr_context {
+	struct _aarch64_ctx head;
+	unsigned long esr;
+};
+#else
+typedef struct {
+	long double __regs[18+256];
+} 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;
+	sigset_t uc_sigmask;
+	mcontext_t uc_mcontext;
+} 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