package/util-linux: fix build with uclibc-ng < 1.0.42

Define static_assert if needed to avoid the following build failure with
uclibc-ng < 1.0.42 raised since bump to version 2.39 in commit
ad276d94a392fb13244e042851a44269e6254d61 and
https://github.com/util-linux/util-linux/commit/0ff57406522ba78ba829df7a64903b3066afb75f:

/home/buildroot/autobuild/run/instance-0/output-1/host/opt/ext-toolchain/bin/../lib/gcc/arm-buildroot-linux-uclibcgnueabihf/9.3.0/../../../../arm-buildroot-linux-uclibcgnueabihf/bin/ld: ./.libs/libsmartcols.so: undefined reference to `static_assert'

Fixes:
 - http://autobuild.buildroot.org/results/c3d38d92557ee9e59b717b85f6307810d5de1487

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/util-linux/util-linux-libs/util-linux-libs.mk

@@ -52,6 +52,9 @@ UTIL_LINUX_LIBS_CONF_OPTS += --disable-widechar
 # No libs use ncurses
 UTIL_LINUX_LIBS_CONF_OPTS += --without-ncursesw --without-ncurses
 
+# workaround for static_assert on uclibc-ng < 1.0.42
+UTIL_LINUX_LIBS_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -Dstatic_assert=_Static_assert"
+
 # Unfortunately, the util-linux does LIBS="" at the end of its
 # configure script. So we have to pass the proper LIBS value when
 # calling the configure script to make configure tests pass properly,

package/util-linux/util-linux.mk

@@ -96,6 +96,9 @@ endif
 UTIL_LINUX_CONF_OPTS += --without-ncursesw --without-ncurses
 endif
 
+# workaround for static_assert on uclibc-ng < 1.0.42
+UTIL_LINUX_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -Dstatic_assert=_Static_assert"
+
 # Unfortunately, the util-linux does LIBS="" at the end of its
 # configure script. So we have to pass the proper LIBS value when
 # calling the configure script to make configure tests pass properly,