[clang] Bugfix for chosing the correct deduction guide (PR #66487)

[Shafik Yaghmour via cfe-commits]

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@@ -85,3 +85,13 @@ int main() {
 
 
 }
+
+namespace deduceTemplatedConstructor{
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shafik wrote:

I apologize for asking you to do additional work here but can you add the rest of the examples from [over.match.best.general p2.13](http://eel.is/c++draft/over.match.best.general#2.13).

It looks like we get all the test correct: https://godbolt.org/z/5MPrErPrq

and it would be nice to have those tests to prevent any possible future regressions.

https://github.com/llvm/llvm-project/pull/66487