[llvm] [LLVM][Demangle] Fix MS Demangler to be stricter about wide string literals (PR #134483)

[Mariya Podchishchaeva via llvm-commits]

================
@@ -70,6 +70,8 @@ Changes to LLVM infrastructure
 
 * Removed support for target intrinsics being defined in the target directories
   themselves (i.e., the `TargetIntrinsicInfo` class).
+* Fix Microsoft demanling of string literals to be stricter
----------------
Fznamznon wrote:

```suggestion
* Fix Microsoft demangling of string literals to be stricter
```

https://github.com/llvm/llvm-project/pull/134483