[clang] pointer to member with qualified-id enclosed in parentheses in...

[clang] pointer to member with qualified-id enclosed in parentheses in unevaluated context should be invalid (#89713)

clang don't check whether the operand of the & operator is enclosed in
parantheses when pointer to member is formed in unevaluated context, for
example:

```cpp
struct foo { int val; };

int main() { decltype(&(foo::val)) ptr; }
```

`decltype(&(foo::val))` should be invalid, but clang accepts it. This PR
fixes this issue.

Fixes #40906.

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Co-authored-by: cor3ntin <corentinjabot@gmail.com>