Add config version, and invalidate layout on config change (#1674)

Summary:
X-link: https://github.com/facebook/react-native/pull/45259

This is a continuation of the previous PR: https://github.com/facebook/react-native/pull/45047

I made the change more generic for allowing any kind of config change to invalidate layout.

Changelog: [Internal]

Pull Request resolved: https://github.com/facebook/yoga/pull/1674

Reviewed By: rozele

Differential Revision: D59286992

Pulled By: NickGerleman

fbshipit-source-id: f46f35b03d5d9a743b798844ee3e1a02c271ccde

yoga/node/LayoutResults.cpp

@@ -21,6 +21,7 @@ bool LayoutResults::operator==(LayoutResults layout) const {
       direction() == layout.direction() &&
       hadOverflow() == layout.hadOverflow() &&
       lastOwnerDirection == layout.lastOwnerDirection &&
+      configVersion == layout.configVersion &&
       nextCachedMeasurementsIndex == layout.nextCachedMeasurementsIndex &&
       cachedLayout == layout.cachedLayout &&
       computedFlexBasis == layout.computedFlexBasis;

yoga/node/LayoutResults.h

@@ -30,6 +30,7 @@ struct LayoutResults {
   // Instead of recomputing the entire layout every single time, we cache some
   // information to break early when nothing changed
   uint32_t generationCount = 0;
+  uint32_t configVersion = 0;
   Direction lastOwnerDirection = Direction::Inherit;
 
   uint32_t nextCachedMeasurementsIndex = 0;

yoga/node/Node.cpp

@@ -136,6 +136,11 @@ void Node::setConfig(yoga::Config* config) {
 
   if (yoga::configUpdateInvalidatesLayout(*config_, *config)) {
     markDirtyAndPropagate();
+    layout_.configVersion = 0;
+  } else {
+    // If the config is functionally the same, then align the configVersion so
+    // that we can reuse the layout cache
+    layout_.configVersion = config->getVersion();
   }
 
   config_ = config;