Swap child Yoga

Summary:
Changelog: [Internal]

Expose the replaceChild Yoga call to Java

Reviewed By: SidharthGuglani

Differential Revision: D19497193

fbshipit-source-id: 153243cc1d8c23dcaf2c772ca794bd59a230f652

yoga/Yoga.cpp

@@ -386,6 +386,14 @@ YOGA_EXPORT void YGNodeInsertChild(
   owner->markDirtyAndPropogate();
 }
 
+YOGA_EXPORT void YGNodeSwapChild(
+    const YGNodeRef owner,
+    const YGNodeRef child,
+    const uint32_t index) {
+  owner->replaceChild(child, index);
+  child->setOwner(owner);
+}
+
 YOGA_EXPORT void YGNodeRemoveChild(
     const YGNodeRef owner,
     const YGNodeRef excludedChild) {