[Bug c++/128506] New: internal compiler error: in finish_qualified_id_expr, at cp/semantics.cc

[0599jiangyc at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128506

            Bug ID: 128506
           Summary: internal compiler error: in finish_qualified_id_expr,
                    at cp/semantics.cc
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: 0599jiangyc at gmail dot com
  Target Milestone: ---

The following code:
```cpp
int S, s;
template<auto ns>
void h ()
{
  namespace A = [:ns:];
  S < A::template X > s;
}
```

Resulted in this output:
```
<source>:6:19: internal compiler error: in finish_qualified_id_expr, at
cp/semantics.cc:2965
```

Trunk reproducer (`-std=c++26 -freflection`): https://godbolt.org/z/dWW5sbhdG