Merge branch '4098-remove-cruft-epoll-kqueue-configure-options-9.18' into 'bind-9.18'

[9.18] Remove obsolete epoll/kqueue/devpoll configure options

See merge request isc-projects/bind9!7975

CHANGES

@@ -1,3 +1,6 @@
+6182.	[cleanup]	Remove configure checks for epoll, kqueue and
+			/dev/poll. [GL #4098]
+
 6181.	[func]		The "tkey-dhkey" option has been deprecated; a
 			warning will be logged when it is used. In a future
 			release, Diffie-Hellman TKEY mode will be removed.

configure.ac

@@ -405,42 +405,6 @@ AC_COMPILE_IFELSE(
 #
 AX_GCC_FUNC_ATTRIBUTE([returns_nonnull])
 
-#
-# check if we have kqueue
-#
-# [pairwise: --enable-kqueue, --disable-kqueue]
-AC_ARG_ENABLE([kqueue],
-	      [AS_HELP_STRING([--enable-kqueue],
-			      [use BSD kqueue when available [default=yes]])],
-	      [], enable_kqueue="yes")
-
-AS_IF([test "$enable_kqueue" = "yes"],
-      [AC_CHECK_FUNCS([kqueue])])
-
-#
-# check if we have epoll.  Linux kernel 2.4 has epoll_create() which fails,
-# so we need to try running the code, not just test its existence.
-#
-# [pairwise: --enable-epoll, --disable-epoll]
-AC_ARG_ENABLE([epoll],
-	      [AS_HELP_STRING([--enable-epoll],
-			      [use Linux epoll when available [default=auto]])],
-	      [], [enable_epoll="yes"])
-
-AS_IF([test "$enable_epoll" = "yes"],
-      [AC_CHECK_FUNCS([epoll_create1])])
-
-#
-# check if we support /dev/poll
-#
-# [pairwise: --enable-devpoll, --disable-devpoll]
-AC_ARG_ENABLE([devpoll],
-	      [AS_HELP_STRING([--enable-devpoll],
-			      [use /dev/poll when available [default=yes]])],
-	      [], [enable_devpoll="yes"])
-AS_IF([test "$enable_devpoll" = "yes"],
-      [AC_CHECK_HEADERS([sys/devpoll.h devpoll.h])])
-
 #
 # GeoIP support?
 #