[Fizz] Don't bail out of flushing if we still have pending root tasks (…

…#27385)

The idea for this check is that we shouldn't flush anything before we
flush the shell. That may or may not hold true in future formats like
RN.

It is a problem for resuming because with resuming it's possible to have
root tasks that are used for resuming but the shell was already flushed
so we can have completed boundaries before the shell has fully resumed.
What matters is whether the parent has already flushed or not.

It's not technically necessary to bail early because there won't be
anything in partialBoundaries or completedBoundaries because nothing
gets added there unless the parent has already flushed.

It's not exactly slow to have to check the length of three arrays so
it's probably not a big deal.

Flush partials in an early preamble needs further consideration
regardless.

DiffTrain build for [df061b3](df061b3)

compiled/facebook-www/REVISION

@@ -1 +1 @@
-a5fc797db14c6e05d4d5c4dbb22a0dd70d41f5d5
+df061b396644bb7c27ea76bb27ae09784ce6444b

compiled/facebook-www/ReactDOMServer-dev.classic.js

@@ -19,7 +19,7 @@ if (__DEV__) {
 var React = require("react");
 var ReactDOM = require("react-dom");
 
-var ReactVersion = "18.3.0-www-classic-0e5abf05";
+var ReactVersion = "18.3.0-www-classic-aa8d23ac";
 
 // This refers to a WWW module.
 var warningWWW = require("warning");
@@ -12734,9 +12734,6 @@ function flushCompletedQueues(request, destination) {
         // We haven't flushed the root yet so we don't need to check any other branches further down
         return;
       }
-    } else if (request.pendingRootTasks > 0) {
-      // We have not yet flushed the root segment so we early return
-      return;
     }
 
     if (enableFloat) {

compiled/facebook-www/ReactDOMServer-dev.modern.js

@@ -19,7 +19,7 @@ if (__DEV__) {
 var React = require("react");
 var ReactDOM = require("react-dom");
 
-var ReactVersion = "18.3.0-www-modern-cdbd1bd5";
+var ReactVersion = "18.3.0-www-modern-d883bcc4";
 
 // This refers to a WWW module.
 var warningWWW = require("warning");
@@ -12482,9 +12482,6 @@ function flushCompletedQueues(request, destination) {
         // We haven't flushed the root yet so we don't need to check any other branches further down
         return;
       }
-    } else if (request.pendingRootTasks > 0) {
-      // We have not yet flushed the root segment so we early return
-      return;
     }
 
     if (enableFloat) {

compiled/facebook-www/ReactDOMServer-prod.classic.js

@@ -4673,7 +4673,6 @@ function flushCompletedQueues(request, destination) {
         request.completedRootSegment = null;
         writeBootstrap(destination, request.resumableState);
       } else return;
-    else if (0 < request.pendingRootTasks) return;
     var resumableState$jscomp$0 = request.resumableState,
       renderState$jscomp$0 = request.renderState;
     completedRootSegment = 0;
@@ -4982,4 +4981,4 @@ exports.renderToString = function (children, options) {
     'The server used "renderToString" which does not support Suspense. If you intended for this Suspense boundary to render the fallback content on the server consider throwing an Error somewhere within the Suspense boundary. If you intended to have the server wait for the suspended component please switch to "renderToReadableStream" which supports Suspense on the server'
   );
 };
-exports.version = "18.3.0-www-classic-a4131db0";
+exports.version = "18.3.0-www-classic-23e62ea1";

compiled/facebook-www/ReactDOMServer-prod.modern.js

@@ -4641,7 +4641,6 @@ function flushCompletedQueues(request, destination) {
         request.completedRootSegment = null;
         writeBootstrap(destination, request.resumableState);
       } else return;
-    else if (0 < request.pendingRootTasks) return;
     var resumableState$jscomp$0 = request.resumableState,
       renderState$jscomp$0 = request.renderState;
     completedRootSegment = 0;
@@ -4950,4 +4949,4 @@ exports.renderToString = function (children, options) {
     'The server used "renderToString" which does not support Suspense. If you intended for this Suspense boundary to render the fallback content on the server consider throwing an Error somewhere within the Suspense boundary. If you intended to have the server wait for the suspended component please switch to "renderToReadableStream" which supports Suspense on the server'
   );
 };
-exports.version = "18.3.0-www-modern-1f4ab623";
+exports.version = "18.3.0-www-modern-794da4f9";

compiled/facebook-www/ReactDOMServerStreaming-dev.modern.js

@@ -12382,9 +12382,6 @@ function flushCompletedQueues(request, destination) {
         // We haven't flushed the root yet so we don't need to check any other branches further down
         return;
       }
-    } else if (request.pendingRootTasks > 0) {
-      // We have not yet flushed the root segment so we early return
-      return;
     }
 
     if (enableFloat) {

compiled/facebook-www/ReactDOMServerStreaming-prod.modern.js

@@ -4334,7 +4334,6 @@ function flushCompletedQueues(request, destination) {
         request.completedRootSegment = null;
         writeBootstrap(destination, request.resumableState);
       } else return;
-    else if (0 < request.pendingRootTasks) return;
     var resumableState$jscomp$0 = request.resumableState,
       renderState$jscomp$0 = request.renderState;
     completedRootSegment = 0;

compiled/facebook-www/ReactTestRenderer-dev.modern.js

@@ -24360,7 +24360,7 @@ function createFiberRoot(
   return root;
 }
 
-var ReactVersion = "18.3.0-www-modern-daf19545";
+var ReactVersion = "18.3.0-www-modern-9be4c0a0";
 
 // Might add PROFILE later.