relibc: fix freeaddrinfo memory leak for unknown address lengths

Previously when getaddrinfo returned an addrinfo with an
ai_addrlen that didn't match sockaddr_in or sockaddr_in6, the
allocation was leaked (the function logged a TODO and returned
without freeing the address).

Now handles:
- sockaddr_un (Unix domain socket addresses)
- ai_addrlen=0 (no address to free)
- Unknown sizes (free as raw allocation to prevent leak)

The raw dealloc uses the address length as the size with
sa_family_t alignment, which is sufficient for any address
family's alignment requirements.

src/header/netdb/mod.rs

@@ -1069,10 +1069,22 @@ pub unsafe extern "C" fn freeaddrinfo(res: *mut addrinfo) {
                 unsafe { drop(Box::from_raw(bai.ai_addr.cast::<sockaddr_in>())) };
             } else if bai.ai_addrlen == mem::size_of::<sockaddr_in6>() as socklen_t {
                 unsafe { drop(Box::from_raw(bai.ai_addr.cast::<sockaddr_in6>())) };
+            } else if bai.ai_addrlen == mem::size_of::<sockaddr_un>() as socklen_t {
+                unsafe { drop(Box::from_raw(bai.ai_addr.cast::<sockaddr_un>())) };
+            } else if bai.ai_addrlen == 0 {
+                // No address to free.
             } else {
-                todo_skip!(0, "freeaddrinfo: unknown ai_addrlen {}", bai.ai_addrlen);
+                // Unknown ai_addrlen — free as raw allocation to avoid leak.
+                let layout = alloc::alloc::Layout::from_size_align(
+                    bai.ai_addrlen as usize,
+                    mem::align_of::<libc::sa_family_t>(),
+                ).unwrap_or(alloc::alloc::Layout::new::<u8>());
+                unsafe {
+                    alloc::alloc::dealloc(bai.ai_addr.cast::<u8>(), layout);
+                }
             }
         }
+        }
         ai = bai.ai_next;
     }
 }