[clang] [clang] Correct Microsoft mangling of lifetime extended temporary objects. (PR #85529)

[Tom Honermann via cfe-commits]

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@@ -54,6 +54,12 @@ ABI Changes in This Version
   inline member function that contains a static local variable with a dynamic
   initializer is declared with ``__declspec(dllimport)``. (#GH83616).
 
+- Fixed Microsoft name mangling of lifetime extended temporary objects. This
+  change corrects missing back reference registrations that could result in
+  incorrect back reference indexes and suprising demangled name results. Since
+  MSVC uses a different mangling for these objects, compatibility is not affected.
+  (#GH85423).
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tahonermann wrote:

A new issue to address the inconsistent use of the `$S<discriminator>` mangling (as well as an additional issue with mangling of anonymous unions) has been filed as #86525.

https://github.com/llvm/llvm-project/pull/85529