Re: [PATCH v4 0/1] MR5211: ntdll/unix: Use termios2 for serial when possible.

[Kirill Zhumarin (＠kirill.zhumarin)]

Thanks for the feedback!

For some unknown and strange reasons, `asm/termbits.h` and `termios.h` are not compatible due to the same #define's. I think dedicated `serial_termios2.c` is the only way to support termios2 in the existing code.

I made the following changes:

- All changes merged into a single commit.
- Changes to `./configure` removed, checking for `asm/termios.h` now in `configure.ac`.
- Fallback logic is rewritten. No more double or false-positive errors.