[Bug c++/108047] [13 Regression] ICE: unexpected expression of kind implicit_conv_expr since r13-4564-gd081807d8d70e3e8

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108047

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:01ea66a6c56e53163d9430f4d87615d570848aa8

commit r13-5075-g01ea66a6c56e53163d9430f4d87615d570848aa8
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Jan 9 23:41:20 2023 +0100

    c++: Only do maybe_init_list_as_range optimization if
!processing_template_decl [PR108047]

    The last testcase in this patch ICEs, because
    maybe_init_list_as_range -> maybe_init_list_as_array
    calls maybe_constant_init in:
      /* Don't do this if the conversion would be constant.  */
      first = maybe_constant_init (first);
      if (TREE_CONSTANT (first))
        return NULL_TREE;
    but maybe_constant_init shouldn't be called when processing_template_decl.
    While we could replace that call with fold_non_dependent_init, my limited
    understanding is that this is an optimization and even if we don't optimize
    it when processing_template_decl, build_user_type_conversion_1 will be
    called again during instantiation with !processing_template_decl if it is
    every instantiated and we can do the optimization only then.

    2023-01-09  Jakub Jelinek  <jakub@redhat.com>

            PR c++/105838
            PR c++/108047
            PR c++/108266
            * call.cc (maybe_init_list_as_range): Always return NULL_TREE if
            processing_template_decl.

            * g++.dg/tree-ssa/initlist-opt2.C: New test.
            * g++.dg/tree-ssa/initlist-opt3.C: New test.