[clang] [clang codegen] Fix MS ABI detection of user-provided constructors. (PR #90151)

[via cfe-commits]

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@@ -201,3 +201,17 @@ S11 f11() {
   S11 x;
   return func11(x);
 }
+
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cor3ntin wrote:

```suggestion

//GH86384
```

https://github.com/llvm/llvm-project/pull/90151