[clang] [Clang] Fix __is_trivially_equality_comparable returning true with ineligebile defaulted overloads (PR #93113)

[Amirreza Ashouri via cfe-commits]

AMP999 wrote:

This patch seems to break the following example (works in trunk, breaks after this patch). Could you please add a test case for this?
https://godbolt.org/z/rdn74xn9M
```
struct S {
  bool operator==(const S&) const = default;
};
struct Derived : S {
  int j_ = 0;
};

static_assert(!__is_trivially_equality_comparable(S));
static_assert(!__is_trivially_equality_comparable(Derived));

bool test1(Derived& a, Derived& b) {
  return a == b;
}

bool test2(Derived& a, Derived& b) {
  return a.j_ == b.j_;
}
```

https://github.com/llvm/llvm-project/pull/93113