bash: Adding features that can not be automatically detected while cross-compiling

There are some bash features that can not be detected automatically during
configure stage while cross-compiling. This commit forces them on.

Signed-off-by: Arkady Gilinsky <arcadyg@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/bash/bash.mk

@@ -7,7 +7,11 @@
 BASH_VERSION = 4.2
 BASH_SITE = $(BR2_GNU_MIRROR)/bash
 BASH_DEPENDENCIES = ncurses
-BASH_CONF_ENV = bash_cv_job_control_missing=no
+BASH_CONF_ENV +=                       \
+   bash_cv_job_control_missing=present \
+   bash_cv_sys_named_pipes=present     \
+   bash_cv_func_sigsetjmp=present      \
+   bash_cv_printf_a_format=yes
 
 # Make sure we build after busybox so that /bin/sh links to bash
 ifeq ($(BR2_PACKAGE_BUSYBOX),y)