[Bug libstdc++/96657] [9/10/11 Regression] libsupc++.a missing required functions from src/c++98/atomicity.cc when atomic builtins are not supported

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96657

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
For completeness, here's a testcase which fails on sparc64-unknown-linux-gnu
when compiled using gcc -m32 eh.C -lsupc++

#include <exception>

int main()
{
  std::make_exception_ptr(1);
}

/usr/bin/ld:
/home/jwakely/gcc/11/lib/gcc/sparc64-unknown-linux-gnu/11.0.1/../../../../lib32/libsupc++.a(eh_ptr.o):
in function `__gnu_cxx::__exchange_and_add_dispatch(int*, int)':
/home/jwakely/build/sparc64-unknown-linux-gnu/32/libstdc++-v3/include/ext/atomicity.h:101:
undefined reference to `__gnu_cxx::__exchange_and_add(int volatile*, int)'
/usr/bin/ld:
/home/jwakely/gcc/11/lib/gcc/sparc64-unknown-linux-gnu/11.0.1/../../../../lib32/libsupc++.a(eh_ptr.o):
in function `__gnu_cxx::__atomic_add_dispatch(int*, int)':
/home/jwakely/build/sparc64-unknown-linux-gnu/32/libstdc++-v3/include/ext/atomicity.h:111:
undefined reference to `__gnu_cxx::__atomic_add(int volatile*, int)'
/usr/bin/ld:
/home/jwakely/gcc/11/lib/gcc/sparc64-unknown-linux-gnu/11.0.1/../../../../lib32/libsupc++.a(eh_ptr.o):
in function `__gnu_cxx::__exchange_and_add_dispatch(int*, int)':
/home/jwakely/build/sparc64-unknown-linux-gnu/32/libstdc++-v3/include/ext/atomicity.h:101:
undefined reference to `__gnu_cxx::__exchange_and_add(int volatile*, int)'
/usr/bin/ld:
/home/jwakely/gcc/11/lib/gcc/sparc64-unknown-linux-gnu/11.0.1/../../../../lib32/libsupc++.a(eh_ptr.o):
in function `__gnu_cxx::__atomic_add_dispatch(int*, int)':
/home/jwakely/build/sparc64-unknown-linux-gnu/32/libstdc++-v3/include/ext/atomicity.h:111:
undefined reference to `__gnu_cxx::__atomic_add(int volatile*, int)'
/usr/bin/ld:
/home/jwakely/gcc/11/lib/gcc/sparc64-unknown-linux-gnu/11.0.1/../../../../lib32/libsupc++.a(eh_throw.o):
in function `__gnu_cxx::__exchange_and_add_dispatch(int*, int)':
/home/jwakely/build/sparc64-unknown-linux-gnu/32/libstdc++-v3/include/ext/atomicity.h:101:
undefined reference to `__gnu_cxx::__exchange_and_add(int volatile*, int)'
collect2: error: ld returned 1 exit status