merge forward from the python 2.x branch
diff --git a/configure.in b/configure.in
index b3d5158..b37226a 100644
--- a/configure.in
+++ b/configure.in
@@ -2580,7 +2580,7 @@
select sem_open sem_timedwait sem_getvalue sem_unlink setegid seteuid \
setgid \
setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setuid setvbuf \
- sigaction siginterrupt sigrelse snprintf strftime strlcpy \
+ sigaction siginterrupt signalfd sigprocmask sigrelse snprintf strftime strlcpy \
sysconf tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
truncate uname unsetenv utimes waitpid wait3 wait4 \
wcscoll wcsftime wcsxfrm _getpty)