Unable to compile Expect

Configuring Expect for /tools succeeds with PTY_TYPE=termios but fails to compile:

```
exp_inter.c: In function "Exp_InteractObjCmd":
exp_inter.c:763:13: error: storage size of "tty_old" isn't known
   763 |      exp_tty tty_old;
       |      ^~~~~~~~~~~~~
```

Cross-GCC in /cross-tools and GCC in /tools compile with the same error. If I use the host's GCC, expect compiles fine.