[Bug c++/93689] ICE with default argument in lambda used as non type template argument

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93689

--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Actually the issue might be just one, even the gimplifier ICE seems to be
caused by a CAST_EXPR leaking where it should not.  Maybe we fail to substitute
default arguments in lambdas in a template parameter list.