LibWeb: Add CSS::Size::is_intrinsic_sizing_constraint()

Author: https://github.com/gmta
Commit: f9b4fa9702
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6695
Reviewed-by: https://github.com/awesomekling ✅

Libraries/LibWeb/CSS/Size.h

@@ -47,6 +47,7 @@ public:
     bool is_none() const { return m_type == Type::None; }
     Type type() const { return m_type; }
 
+    bool is_intrinsic_sizing_constraint() const { return is_min_content() || is_max_content() || is_fit_content(); }
     bool is_length_percentage() const { return is_length() || is_percentage() || is_calculated(); }
 
     [[nodiscard]] CSSPixels to_px(Layout::Node const&, CSSPixels reference_value) const;