Fix absolute position if wrap-reverse and align-items: flex-end

Summary:
This is a fix on top of 56b10fc. It takes the case into account were you have `wrap-reverse` and `align-items: flex-end` set.
Closes facebook/yoga#568

Differential Revision: D5155521

Pulled By: emilsjolander

fbshipit-source-id: 7e5fcfa2fbb48b6c6279da46cc648a071ff2b079

ReactCommon/yoga/yoga/Yoga.c

@@ -1714,7 +1714,7 @@ static void YGNodeAbsoluteLayoutChild(const YGNodeRef node,
          child->layout.measuredDimensions[dim[crossAxis]]) /
         2.0f;
   } else if (!YGNodeIsLeadingPosDefined(child, crossAxis) &&
-             (YGNodeAlignItem(node, child) == YGAlignFlexEnd || node->style.flexWrap == YGWrapWrapReverse)) {
+             ((YGNodeAlignItem(node, child) == YGAlignFlexEnd) ^ (node->style.flexWrap == YGWrapWrapReverse))) {
     child->layout.position[leading[crossAxis]] = (node->layout.measuredDimensions[dim[crossAxis]] -
                                                   child->layout.measuredDimensions[dim[crossAxis]]);
   }