https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127710
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I suspect it's due to us creating *&TARGET_EXPR <D.2704, {}> in
if (is_really_empty_class (type, /*ignore_vptr*/true))
{
/* Avoid copying empty classes, but ensure op= returns an lvalue even
if the object argument isn't one. */
to = force_lvalue (to, complain);
val = build2 (COMPOUND_EXPR, type, arg, to);
suppress_warning (val, OPT_Wunused);
}
where we want an lvalue, but then the *& are removed somewhere and we end up
with a prvalue.
