[Bug c++/90448] [8/9/10 Regression] decltype-based lambda parameter pack is rejected

[paolo.carlini at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90448

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> ---
This is already fixed in trunk: I'm adding the testcase and removingg the 10
Regression marker.