[Bug c++/106864] Const int captured could be avoid even if used by nested lambda

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106864

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
prune_lambda_captures is supposed to prune these but it looks like it is not
pruning it always.