See https://godbolt.org/z/ecYjGsWo7.
```C++
#include <cassert>
int main() {
  [i=0]() consteval /*mutable*/ {
    ++*(int*)(void*)&i;
    assert(i == 1);
  }();
}
```

A minimal reproduction:
```C++
int main() {
  [i=0]() consteval {
    (void)+*(const int*)(const void*)&i;
  }();
}
```

Discovered at https://cpplang.slack.com/archives/C263VAF2B/p1630942490163700?thread_ts=1630937296.159200&cid=C263VAF2B.