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

fusl/src/fcntl/open.c

Index: fusl/src/fcntl/open.c
diff --git a/fusl/src/fcntl/open.c b/fusl/src/fcntl/open.c
new file mode 100644
index 0000000000000000000000000000000000000000..3928a6e6696f05106e81bfd70a84210ce431e62a
--- /dev/null
+++ b/fusl/src/fcntl/open.c
@@ -0,0 +1,24 @@
+#include <fcntl.h>
+#include <stdarg.h>
+#include "syscall.h"
+#include "libc.h"
+
+int open(const char *filename, int flags, ...)
+{
+	mode_t mode = 0;
+
+	if ((flags & O_CREAT) || (flags & O_TMPFILE) == O_TMPFILE) {
+		va_list ap;
+		va_start(ap, flags);
+		mode = va_arg(ap, mode_t);
+		va_end(ap);
+	}
+
+	int fd = __sys_open_cp(filename, flags, mode);
+	if (fd>=0 && (flags & O_CLOEXEC))
+		__syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC);
+
+	return __syscall_ret(fd);
+}
+
+LFS64(open);