LibWeb: Break lines until we have enough space between floats

Before this change, we'd always insert one line box fragment, even when
a float was taking up too much space on the line, and the fragment
didn't actually fit.

We now perform line breaks until we have enough space between floats.
This fixes many page layouts where we'd previously see small fragments
of inline content outside the right edge of the containing block.

Userland/Libraries/LibWeb/Layout/InlineFormattingContext.cpp

@@ -297,4 +297,12 @@ void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
     }
 }
 
+bool InlineFormattingContext::any_floats_intrude_at_y(float y) const
+{
+    auto box_in_root_rect = content_box_rect_in_ancestor_coordinate_space(containing_block(), parent().root(), m_state);
+    float y_in_root = box_in_root_rect.y() + y;
+    auto space = parent().space_used_by_floats(y_in_root);
+    return space.left > 0 || space.right > 0;
+}
+
 }