[Bug c++/99571] New: ICE for NTTP with pointer to array of union

[johelegp at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99571

            Bug ID: 99571
           Summary: ICE for NTTP with pointer to array of union
           Product: gcc
           Version: 11.0
               URL: https://godbolt.org/z/rsc6fs
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: johelegp at gmail dot com
                CC: johelegp at gmail dot com
  Target Milestone: ---

See https://godbolt.org/z/rsc6fs.
```C++
struct I{
  union { int a[1]{}; };
  int*i=a;
};
constexpr I i;
template<auto>struct C{};
[[maybe_unused]]C<i>c;
```