cmake HAVE_PTY_H examples

CTSRD-CHERI/cheribsd contrib/nvi/CMakeLists.txt :228 

check_include_files(pty.h HAVE_PTY_H)

FujiNetWIFI/fujinet-firmware components_pc/libssh/ConfigureChecks.cmake :51 

check_include_file(pty.h HAVE_PTY_H)