[Bug c++/111357] [11/12/13/14 Regression] __integer_pack fails to work with values of dependent type convertible to integers in noexcept context

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111357

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Seems when expand_integer_pack is called first time, ohi is
TEMPLATE_PARAMETER_INDEX
with the right type (_Tp TEMPLATE_TYPE_PARM), but when it calls
  tree hi = tsubst_copy_and_build (ohi, args, complain, in_decl);
it returns an empty CONSTRUCTOR with c1 type.
Dunno if the bug is that tsubst didn't convert it to _Tp type or if it would be
normally a task for something done later on.
And we then
      if (hi != ohi)
        {
          call = copy_node (call);
          CALL_EXPR_ARG (call, 0) = hi;
        }