Trying to link a binary against libc++ will result in a linker error due to missing libunwind:

```
# echo "int main(){return 0 ;}" | clang++ -x c++  --stdlib=libc++ -o test - 
/usr/bin/ld: cannot find -lunwind: No such file or directory
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
```

However libunwind.so.1 is installed and resolved by ldd:
```
# ldd /usr/lib64/libc++.so.1
        linux-vdso64.so.1 (0x000003ffcdbfe000)
        libc++abi.so.1 => /lib64/libc++abi.so.1 (0x000003ffad280000)
        libunwind.so.1 => /lib64/libunwind.so.1 (0x000003ffad200000)
        libc.so.6 => /lib64/libc.so.6 (0x000003ffad000000)
        /lib/ld64.so.1 (0x000003ffad500000)
# rpm -qf /lib64/libunwind.so.1
llvm-libunwind-18.1.0~rc4-1.fc41.s390x
```

If installing `llvm-libunwind-devel` (not installed through deps of libcxx), and we pass the lib directory that it provides, the linkage succeeds:
```
# echo "int main(){return 0 ;}" | clang++ -L/usr/lib64/llvm-unwind -x c++  --stdlib=libc++ -o test - 
# rpm -qf /usr/lib64/llvm-unwind/libunwind.so 
llvm-libunwind-devel-18.1.0~rc4-1.fc41.s390x
```


Reproducible: Always

Steps to Reproduce:
1. dnf install clang libcxx-devel
2. echo "int main(){return 0 ;}" | clang++ -v -x c++  --stdlib=libc++ -o test -

Actual Results:  
/usr/bin/ld: cannot find -lunwind: No such file or directory
clang++: error: linker command failed with exit code 1 (use -v to see invocation)

Expected Results:  
Link successfully

Reproduced in x86_64 and s390x, not tested in aarch64 and ppc64le.
Installed packages:
# rpm -q clang libcxx llvm-libunwind
clang-18.1.0~rc4-2.fc41.s390x
libcxx-18.1.0~rc4-1.fc41.s390x
llvm-libunwind-18.1.0~rc4-1.fc41.s390x