[Bug c++/90548] [9/10 Regression] ICE in tsubst_copy_and_build, at cp/pt.c:18877

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90548

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
(gdb) p (*call_args).is_empty()
$5 = true
so
tree arg = (*call_args)[i];
where i == 0 won't work.