Auto merge of #14518 - mbrubeck:rowspan2, r=notriddle

Fix inline layout of table cells impacted by rowspan

This is part of the fix for #11297. This PR fixes the inline layout of table cells impacted by row-spanning cells from previous rows. A separate PR to follow will fix the table block size calculations to account for rowspan.

This PR doesn't yet include any test changes. If it doesn't cause any existing tests to pass, I will add a new test to it.

r? @pcwalton

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components/script/layout_wrapper.rs

@@ -864,6 +864,12 @@ impl<'ln> ThreadSafeLayoutNode for ServoThreadSafeLayoutNode<'ln> {
             self.get_jsmanaged().downcast::<Element>().unwrap().get_colspan()
         }
     }
+
+    fn get_rowspan(&self) -> u32 {
+        unsafe {
+            self.get_jsmanaged().downcast::<Element>().unwrap().get_rowspan()
+        }
+    }
 }
 
 pub struct ThreadSafeLayoutNodeChildrenIterator<ConcreteNode: ThreadSafeLayoutNode> {