testlib's autotest compilation fails with glibc 2.34

 agent:2021/08/16 15:52:46 build.go:391: In file included from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/recipe-sysroot/usr/include/signal.h:328,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p_p.h:7978,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p.h:56,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch.cpp:47:
agent:2021/08/16 15:52:46 build.go:391: /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p_p.h:10766:58: error: call to non-'constexpr' function 'long int sysconf(int)'
agent:2021/08/16 15:52:46 build.go:391: 10766 |     static constexpr std::size_t sigStackSize = 32768 >= MINSIGSTKSZ ? 32768 : MINSIGSTKSZ;
agent:2021/08/16 15:52:46 build.go:391:       |                                                          ^~~~~~~~~~~
agent:2021/08/16 15:52:46 build.go:391: In file included from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/recipe-sysroot/usr/include/bits/sigstksz.h:24,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/recipe-sysroot/usr/include/signal.h:328,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p_p.h:7978,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p.h:56,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch.cpp:47:
agent:2021/08/16 15:52:46 build.go:391: /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/recipe-sysroot/usr/include/unistd.h:641:17: note: 'long int sysconf(int)' declared here
agent:2021/08/16 15:52:46 build.go:391:   641 | extern long int sysconf (int __name) __THROW;
agent:2021/08/16 15:52:46 build.go:391:       |                 ^~~~~~~
agent:2021/08/16 15:52:46 build.go:391: In file included from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p.h:56,
agent:2021/08/16 15:52:46 build.go:391:                  from /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch.cpp:47:
agent:2021/08/16 15:52:46 build.go:391: /home/qt/work/build/build/tmp/work/core2-32-poky-linux/qtbase/6.3.0-r0/git/tests/auto/testlib/selftests/catch_p_p.h:10825:45: error: size of array 'altStackMem' is not an integral constant-expression
agent:2021/08/16 15:52:46 build.go:391: 10825 |     char FatalConditionHandler::altStackMem[sigStackSize] = {};
agent:2021/08/16 15:52:46 build.go:391:       |                                             ^~~~~~~~~~~~