[Bug c++/108059] internal compiler error: in tsubst_copy, at cp/pt.c:16425

["lh_mouse at 126 dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108059

LIU Hao <lh_mouse at 126 dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |10.3.0, 11.1.0
             Target|                            |x86_64-linux-gnu
               Host|                            |x86_64-linux-gnu

--- Comment #1 from LIU Hao <lh_mouse at 126 dot com> ---
Reduced testcase, also ICEs with GCC 10.3.0 and 11.1.0, but 9.4.0 is fine:

```
template <int> using a = int;
template <int> auto b() {
  [](auto... c) { [](a<c>...) {}; };
}
template <int d> using e = decltype(b<d>);
e<1> f;

```


```
$ g++-10 -std=c++17 test.cc
test.cc: In instantiation of ‘auto b() [with int <anonymous> = 1]’:
test.cc:5:24:   required by substitution of ‘template<int d> using e = decltype
(b<d>) [with int d = 1]’
test.cc:6:4:   required from here
test.cc:3:19: internal compiler error: in tsubst_copy, at cp/pt.c:16425
    3 |   [](auto... c) { [](a<c>...) {}; };
      |                   ^~~~~~~~~~~~~~
0x7f76079c809a __libc_start_main
        ../csu/libc-start.c:308
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions.

```