useFormState: Emit comment to mark whether state matches (#27307)

A planned feature of useFormState is that if the page load is the result
of an MPA-style form submission — i.e. a form was submitted before it
was hydrated, using Server Actions — the state of the hook should
transfer to the next page.

I haven't implemented that part yet, but as a prerequisite, we need some
way for Fizz to indicate whether a useFormState hook was rendered using
the "postback" state. That way we can do all state matching logic on the
server without having to replicate it on the client, too.

The approach here is to emit a comment node for each useFormState hook.
We use one of two comment types: `<!--F-->` for a normal useFormState
hook, and `<!--F!-->` for a hook that was rendered using the postback
state. React will read these markers during hydration. This is similar
to how we encode Suspense boundaries.

Again, the actual matching algorithm is not yet implemented — for now,
the "not matching" marker is always emitted.

We can optimize this further by not emitting any markers for a render
that is not the result of a form postback, which I'll do in subsequent
PRs.

DiffTrain build for commit 8b26f07.

Author: acdlite

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-dev.js

@@ -23994,7 +23994,7 @@ function createFiberRoot(
   return root;
 }
 
-var ReactVersion = "18.3.0-canary-3566de59e-20230907";
+var ReactVersion = "18.3.0-canary-8b26f07a8-20230907";
 
 // Might add PROFILE later.
 

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-prod.js

@@ -8617,7 +8617,7 @@ var devToolsConfig$jscomp$inline_1027 = {
     throw Error("TestRenderer does not support findFiberByHostInstance()");
   },
   bundleType: 0,
-  version: "18.3.0-canary-3566de59e-20230907",
+  version: "18.3.0-canary-8b26f07a8-20230907",
   rendererPackageName: "react-test-renderer"
 };
 var internals$jscomp$inline_1226 = {
@@ -8648,7 +8648,7 @@ var internals$jscomp$inline_1226 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-canary-3566de59e-20230907"
+  reconcilerVersion: "18.3.0-canary-8b26f07a8-20230907"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1227 = __REACT_DEVTOOLS_GLOBAL_HOOK__;

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react-test-renderer/cjs/ReactTestRenderer-profiling.js

@@ -9043,7 +9043,7 @@ var devToolsConfig$jscomp$inline_1069 = {
     throw Error("TestRenderer does not support findFiberByHostInstance()");
   },
   bundleType: 0,
-  version: "18.3.0-canary-3566de59e-20230907",
+  version: "18.3.0-canary-8b26f07a8-20230907",
   rendererPackageName: "react-test-renderer"
 };
 var internals$jscomp$inline_1267 = {
@@ -9074,7 +9074,7 @@ var internals$jscomp$inline_1267 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-canary-3566de59e-20230907"
+  reconcilerVersion: "18.3.0-canary-8b26f07a8-20230907"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1268 = __REACT_DEVTOOLS_GLOBAL_HOOK__;

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-dev.js

@@ -27,7 +27,7 @@ if (
 }
           "use strict";
 
-var ReactVersion = "18.3.0-canary-3566de59e-20230907";
+var ReactVersion = "18.3.0-canary-8b26f07a8-20230907";
 
 // ATTENTION
 // When adding new symbols to this file,

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-prod.js

@@ -616,4 +616,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "18.3.0-canary-3566de59e-20230907";
+exports.version = "18.3.0-canary-8b26f07a8-20230907";

compiled-rn/facebook-fbsource/xplat/js/RKJSModules/vendor/react/cjs/React-profiling.js

@@ -619,7 +619,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "18.3.0-canary-3566de59e-20230907";
+exports.version = "18.3.0-canary-8b26f07a8-20230907";
 
           /* global __REACT_DEVTOOLS_GLOBAL_HOOK__ */
 if (

compiled-rn/facebook-fbsource/xplat/js/react-native-github/Libraries/Renderer/REVISION

@@ -1 +1 @@
-3566de59e2046e7e8478462375aaa71716f1095b
+8b26f07a883bb341c20283c0099bf5ee6f87bd1f