[Bug c++/128541] New: internal compiler error: in mangle_decl_string, at cp/mangle.cc

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128541

            Bug ID: 128541
           Summary: internal compiler error: in mangle_decl_string, at
                    cp/mangle.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
template <class T> struct S { template <class U> __attribute__((target("avx")))
void f (); };
template <class T> template <class U> __attribute__((target("avx512f"))) void
S<T>::f () {}
```

Resulted in this output:
```
<source>:2:88: internal compiler error: in mangle_decl_string, at
cp/mangle.cc:4869
```

Trunk reproducer: https://godbolt.org/z/86TTE1d85