add more errno constants to uclibc

Add more errno constants as requested by rustc since commit
1ec9454403e9bb0361d0725524c4bd27030474cc (for a discussion of the
change, see rust-lang/rust#79965).

The constant values and descriptions were taken from
include/uapi/asm-generic/errno.h in the Linux kernel, since "uClibc will
be compiled to match the interfaces available in the provided version of
the Linux kernel headers".

While the fork of uClibc in L4Re nominally has its own errno constants,
they appear to be based on the Linux header file and thus are the same.

src/unix/linux_like/linux/uclibc/x86_64/mod.rs

@@ -292,15 +292,23 @@ s_no_extra_traits! {
 }
 
 // constants
+pub const ENAMETOOLONG: ::c_int = 36; // File name too long
+pub const ENOTEMPTY: ::c_int = 39; // Directory not empty
+pub const ELOOP: ::c_int = 40; // Too many symbolic links encountered
 pub const EADDRINUSE: ::c_int = 98; // Address already in use
 pub const EADDRNOTAVAIL: ::c_int = 99; // Cannot assign requested address
+pub const ENETDOWN: ::c_int = 100; // Network is down
+pub const ENETUNREACH: ::c_int = 101; // Network is unreachable
 pub const ECONNABORTED: ::c_int = 103; // Software caused connection abort
 pub const ECONNREFUSED: ::c_int = 111; // Connection refused
 pub const ECONNRESET: ::c_int = 104; // Connection reset by peer
 pub const EDEADLK: ::c_int = 35; // Resource deadlock would occur
 pub const ENOSYS: ::c_int = 38; // Function not implemented
 pub const ENOTCONN: ::c_int = 107; // Transport endpoint is not connected
 pub const ETIMEDOUT: ::c_int = 110; // connection timed out
+pub const ESTALE: ::c_int = 116; // Stale file handle
+pub const EHOSTUNREACH: ::c_int = 113; // No route to host
+pub const EDQUOT: ::c_int = 122; // Quota exceeded
 pub const EOPNOTSUPP: ::c_int = 0x5f;
 pub const ENODATA: ::c_int = 0x3d;
 pub const O_APPEND: ::c_int = 02000;