[Bug c++/98105] constexpr and unnamed namespace yields relocation R_X86_64_PC32 against undefined symbol ... can not be used when making a shared object; recompile with -fPIC

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98105

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced:
```
void f(const int&);

namespace {
  struct myFactory
  {
    static constexpr int s_sList = 1;
  };
}
//constexpr int myFactory::s_sList;
void sdi_register_model()
{
  f(myFactory::s_sList);
}
```

If we uncomment the definition, it works.

I think this is correct behavior, just we should produce a better error message
of not have the definition and only the declaration here.