[clang] [C23] Fix typeof handling in enum declarations (PR #146394)

[via cfe-commits]

yronglin wrote:

> ```c++
> typeof(int){} x; // Probably parsed as typeof(int{})
> ```

GCC reject this https://godbolt.org/z/YEdnGh8T5

https://github.com/llvm/llvm-project/pull/146394