[libcxx-commits] [libcxx] [libc++] Fixes istream::sync. (PR #76467)

[Louis Dionne via libcxx-commits]

================
@@ -10,6 +10,11 @@
 
 // int sync();
 
+// The fix for bug 51497 and bug 51499 require and updated dylib due to
+// explicit instantiations. That means Apple backdeployment targets remain
+// broken.
+// UNSUPPORTED: using-built-library-before-llvm-19
----------------
ldionne wrote:

```suggestion
// XFAIL: using-built-library-before-llvm-19
```

https://github.com/llvm/llvm-project/pull/76467