[clang] [Clang][Sema] Earlier type checking for builtin unary operators (PR #90500)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

Well this took forever to reduce:
```cpp
template<typename T>
struct A;

template<typename T>
bool operator==(const A<T>&, const A<T>&);

template<typename>
void f(int *x)
{
    [&](auto *y) { return x == y; };
}

void g()
{
    f<int>(nullptr);
}
```
We initially build a `CXXOperatorCallExpr` during parsing for the comparison, but `TreeTransform` prematurely rebuilds it as a builtin binary operator when `f` is instantiated.

https://github.com/llvm/llvm-project/pull/90500