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

fusl/include/sys/signalfd.h

Index: fusl/include/sys/signalfd.h
diff --git a/fusl/include/sys/signalfd.h b/fusl/include/sys/signalfd.h
new file mode 100644
index 0000000000000000000000000000000000000000..55431b91673c0a16a8731920d94fe0d711287d6d
--- /dev/null
+++ b/fusl/include/sys/signalfd.h
@@ -0,0 +1,45 @@
+#ifndef _SYS_SIGNALFD_H
+#define _SYS_SIGNALFD_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <fcntl.h>
+
+#define __NEED_sigset_t
+
+#include <bits/alltypes.h>
+
+#define SFD_CLOEXEC O_CLOEXEC
+#define SFD_NONBLOCK O_NONBLOCK
+
+int signalfd(int, const sigset_t *, int);
+
+struct signalfd_siginfo {
+	uint32_t  ssi_signo;
+	int32_t   ssi_errno;
+	int32_t   ssi_code;
+	uint32_t  ssi_pid;
+	uint32_t  ssi_uid;
+	int32_t   ssi_fd;
+	uint32_t  ssi_tid;
+	uint32_t  ssi_band;
+	uint32_t  ssi_overrun;
+	uint32_t  ssi_trapno;
+	int32_t   ssi_status;
+	int32_t   ssi_int;
+	uint64_t  ssi_ptr;
+	uint64_t  ssi_utime;
+	uint64_t  ssi_stime;
+	uint64_t  ssi_addr;
+	uint16_t  ssi_addr_lsb;
+	uint8_t   pad[128-12*4-4*8-2];
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif