Changeset 667501a in rtems for testsuites/libtests/configure.ac

termios: Add Capability to Generate SIGINTR and SIGQUIT

This patch adds the ability for termios to send SIGINTR on receipt
of VINTR and SIGQUIT for VKILL and return -1/EINTR from read() on
a termios channel. Importantly, this patch does not alter the default
behavior or force POSIX signal code in just because termios is used.
The application must explicitly enable the POSIX behavior of generating
a signal upon receipt of these characters. This is discussed in the
POSIX standard:

​https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap11.html

Closes #3800.