[Bug c++/99806] New: ICE in tsubst_copy of gcc-trunk and tree_code_size of gcc-10

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99806

            Bug ID: 99806
           Summary: ICE in tsubst_copy of gcc-trunk and tree_code_size of
                    gcc-10
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

https://godbolt.org/z/s687ePeGG


template <class T> concept C = requires (T a) { a.f(0); };
struct S { void f(auto) noexcept(); };
static_assert(C<S>);


gcc-trunk:

<source>:2:17: internal compiler error: in tsubst_copy, at cp/pt.c:17247
    2 | struct S { void f(auto) noexcept(); };
      |                 ^

gcc-10:

<source>:2:17: internal compiler error: in tree_code_size, at tree.c:910
    2 | struct S { void f(auto) noexcept(); };
      |