[Bug c++/90489] Attributes no longer allowed in lambdas with trailing return type

[mathias at gaunard dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90489

--- Comment #1 from Mathias Gaunard <mathias at gaunard dot com> ---
Possibly related,
Both
auto const f = [](int) [[gnu::always_inline]] -> int { return 0; };
and
auto const f = [](int) [[gnu::always_inline]] { return 0; };

also fail with GCC 9.1, but work with GCC 8.2.

says:
<source>:1:50: warning: attribute ignored [-Wattributes]

    1 | auto const f = [](int) [[gnu::always_inline]] -> int { return 0; };

      |                                                  ^~~

<source>:1:50: note: an attribute that appertains to a type-specifier is
ignored