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

fusl/arch/mips/bits/fcntl.h

+#define O_CREAT        0400
+#define O_EXCL        02000
+#define O_NOCTTY      04000
+#define O_TRUNC       01000
+#define O_APPEND       0010
+#define O_NONBLOCK     0200
+#define O_DSYNC        0020
+#define O_SYNC       040020
+#define O_RSYNC      040020
+#define O_DIRECTORY 0200000
+#define O_NOFOLLOW  0400000
+#define O_CLOEXEC  02000000
+
+#define O_ASYNC      010000
+#define O_DIRECT    0100000
+#define O_LARGEFILE  020000
+#define O_NOATIME  01000000
+#define O_PATH    010000000
+#define O_TMPFILE 020200000
+#define O_NDELAY O_NONBLOCK
+
+#define F_DUPFD  0
+#define F_GETFD  1
+#define F_SETFD  2
+#define F_GETFL  3
+#define F_SETFL  4
+
+#define F_SETOWN 24
+#define F_GETOWN 23
+#define F_SETSIG 10
+#define F_GETSIG 11
+
+#define F_GETLK 33
+#define F_SETLK 34
+#define F_SETLKW 35
+
+#define F_SETOWN_EX 15
+#define F_GETOWN_EX 16
+
+#define F_GETOWNER_UIDS 17