[Bug c++/82299] -Wuseless-cast errors on typed enums used in member data initializers in c++1z

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82299

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
{ target c++11 } means the test is run for -std=c++{11,14,17,2a,17 -fconcepts}.
And the test wants to make sure that the warning isn't emitted in any of those
modes.