[libcxxabi] [llvm] [llvm] annotate interfaces in Demangle for DLL export (PR #147564)

[Louis Dionne via llvm-commits]

================
@@ -0,0 +1,18 @@
+//===--- Visibility.h -------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// This file is contains noop definitions of the DEMANGLE_ABI macro defined in
+// llvm/include/llvm/Demangle/Visibility.h.
+//===----------------------------------------------------------------------===//
+
+#ifndef LIBCXXABI_DEMANGLE_VISIBILITY_H
+#define LIBCXXABI_DEMANGLE_VISIBILITY_H
+
+// The DEMANGLE_ABI macro resovles to nothing when building libcxxabi. Only
----------------
ldionne wrote:

```suggestion
// The DEMANGLE_ABI macro resolves to nothing when building libc++abi. Only
```

https://github.com/llvm/llvm-project/pull/147564