Add persistent, Static subtreeTag

This allows certain concepts to persist without recalculting them, e.g. whether a subtree contains passive effects or portals. This helps for cases like nested unmounts that contain deep passive effects.

Author: Brian Vaughn

packages/react-reconciler/src/ReactFiber.new.js

@@ -30,7 +30,10 @@ import {
   enableBlocksAPI,
 } from 'shared/ReactFeatureFlags';
 import {NoEffect, Placement} from './ReactSideEffectTags';
-import {NoEffect as NoSubtreeEffect} from './ReactSubtreeTags';
+import {
+  NoEffect as NoSubtreeEffect,
+  Static as StaticSubtreeEffects,
+} from './ReactSubtreeTags';
 import {ConcurrentRoot, BlockingRoot} from './ReactRootTags';
 import {
   IndeterminateComponent,
@@ -290,7 +293,6 @@ export function createWorkInProgress(current: Fiber, pendingProps: any): Fiber {
     // We already have an alternate.
     // Reset the effect tag.
     workInProgress.effectTag = NoEffect;
-    workInProgress.subtreeTag = NoSubtreeEffect;
     workInProgress.deletions = null;
 
     // The effect list is no longer valid.
@@ -308,6 +310,7 @@ export function createWorkInProgress(current: Fiber, pendingProps: any): Fiber {
     }
   }
 
+  workInProgress.subtreeTag = current.subtreeTag & StaticSubtreeEffects;
   workInProgress.childLanes = current.childLanes;
   workInProgress.lanes = current.lanes;
 

packages/react-reconciler/src/ReactFiberCommitWork.new.js

@@ -881,19 +881,6 @@ function commitUnmount(
               if ((tag & HookPassive) !== NoHookEffect) {
                 effect.tag |= HookHasEffect;
 
-                // subtreeTags bubble in resetChildLanes which doens't get called for unmounted subtrees.
-                // So in the case of unmounts, we need to bubble passive effects explicitly.
-                let ancestor = current.return;
-                while (ancestor !== null) {
-                  ancestor.subtreeTag |= PassiveSubtreeTag;
-                  const alternate = ancestor.alternate;
-                  if (alternate !== null) {
-                    alternate.subtreeTag |= PassiveSubtreeTag;
-                  }
-
-                  ancestor = ancestor.return;
-                }
-
                 current.effectTag |= Passive;
 
                 if (__DEV__) {

packages/react-reconciler/src/ReactSubtreeTags.js

@@ -14,3 +14,8 @@ export const BeforeMutation = /*  */ 0b0001;
 export const Mutation = /*        */ 0b0010;
 export const Layout = /*          */ 0b0100;
 export const Passive = /*         */ 0b1000;
+
+// Union of tags that don't get reset on clones.
+// This allows certain concepts to persist without recalculting them,
+// e.g. whether a subtree contains passive effects or portals.
+export const Static = /*          */ 0b1000;