[Bug c++/63707] Brace initialization of array sometimes fails if no copy constructor

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63707

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced from PR 64887:

struct string
{
  string(const char*) { }
  ~string(); // make this type non-trivial
};

struct A
{
  string s;
  A() = delete;
  A(const A&) = delete;
  A(A&&) = delete;
  A(const char*);
};

A arr[2] = {{"a"}, {"b"}}; // ok

struct Aggr {
  A arr[2];
  Aggr() : arr{{"a"}, {"b"}} {} // error
};

The member of non-trivial type is required to trigger the error, presumably
because it makes the destructor non-trivial.