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

fusl/src/linux/splice.c

Index: fusl/src/linux/splice.c
diff --git a/fusl/src/linux/splice.c b/fusl/src/linux/splice.c
new file mode 100644
index 0000000000000000000000000000000000000000..78b6220d8e615a29b385a5fdb80f41dc75588ced
--- /dev/null
+++ b/fusl/src/linux/splice.c
@@ -0,0 +1,8 @@
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include "syscall.h"
+
+ssize_t splice(int fd_in, off_t *off_in, int fd_out, off_t *off_out, size_t len, unsigned flags)
+{
+	return syscall(SYS_splice, fd_in, off_in, fd_out, off_out, len, flags);
+}