Bug 287554 – Make `Vector::operator==` work correctly with padded structs

• Component: New Bugs
• Status: RESOLVED FIXED

[Antoine Quint]

In 289948@main a workaround was implemented to let two `Vector<StyleRuleKeyframe::Key>` be compared with the `==` operator:

```
    // FIXME: using Vector::operator==() here fails on Intel, so we provide our own logic.
    auto keysAreEqual = [](const Vector<StyleRuleKeyframe::Key>& a, const Vector<StyleRuleKeyframe::Key>& b) {
        if (a.size() != b.size())
            return false;
        for (auto i = a.size(); i--;) {
            if (!(a[i] == b[i]))
                return false;
        }
        return true;
    };
```

Indeed, on Intel, simply using the existing `Vector::operator==` would yield failures in `LayoutTests/animations/keyframes-rule.html`. Apparently this is due to the fact that `memcmp()` is used in this case and that it doesn't work correctly with padded structs like `StyleRuleKeyframe::Key`.

[Radar WebKit Bug Importer]

<rdar://problem/144700872>

[Chris Dumez]

Pull request: https://github.com/WebKit/WebKit/pull/41696

[EWS]

Committed 291724@main (30eb04f14b59): <https://commits.webkit.org/291724@main>

Reviewed commits have been landed. Closing PR #41696 and removing active labels.