build-gnu.sh: Do not build GNU coreutils for faster CI

Author: oech3

util/build-gnu.sh

@@ -130,6 +130,7 @@ if test -f gnu-built; then
 else
     # Disable useless checks
     sed -i 's|check-texinfo: $(syntax_checks)|check-texinfo:|' doc/local.mk
+    export CFLAGS="${CFLAGS} -pipe -std=gnu23"
     ./bootstrap --skip-po
     ./configure --quiet --disable-gcc-warnings --disable-nls --disable-dependency-tracking --disable-bold-man-page-references \
       "$([ "${SELINUX_ENABLED}" = 1 ] && echo --with-selinux || echo --without-selinux)"
@@ -138,7 +139,7 @@ else
     sed -i 's| tr | /usr/bin/tr |' tests/init.sh
     # Use a better diff
     sed -i 's|diff -c|diff -u|g' tests/Coreutils.pm
-    "${MAKE}" -j "$("${NPROC}")"
+    "${MAKE}" -j "$("${NPROC}")" src/getlimits # needed for tests
 
     # Handle generated factor tests
     t_first=00