Add Postpone API (#27238)

This adds an experimental `unstable_postpone(reason)` API.

Currently we don't have a way to model effectively an Infinite Promise.
I.e. something that suspends but never resolves. The reason this is
useful is because you might have something else that unblocks it later.
E.g. by updating in place later, or by client rendering.

On the client this works to model as an Infinite Promise (in fact,
that's what this implementation does). However, in Fizz and Flight that
doesn't work because the stream needs to end at some point. We don't
have any way of knowing that we're suspended on infinite promises. It's
not enough to tag the promises because you could await those and thus
creating new promises. The only way we really have to signal this
through a series of indirections like async functions, is by throwing.
It's not 100% safe because these values can be caught but it's the best
we can do.

Effectively `postpone(reason)` behaves like a built-in [Catch
Boundary](facebook/react#26854). It's like
`raise(Postpone, reason)` except it's built-in so it needs to be able to
be encoded and caught by Suspense boundaries.

In Flight and Fizz these behave pretty much the same as errors. Flight
just forwards it to retrigger on the client. In Fizz they just trigger
client rendering which itself might just postpone again or fill in the
value. The difference is how they get logged.

In Flight and Fizz they log to `onPostpone(reason)` instead of
`onError(error)`. This log is meant to help find deopts on the server
like finding places where you fall back to client rendering. The reason
that you pass in is for that purpose to help the reason for any deopts.

I do track the stack trace in DEV but I don't currently expose it to
`onPostpone`. This seems like a limitation. It might be better to expose
the Postpone object which is an Error object but that's more of an
implementation detail. I could also pass it as a second argument.

On the client after hydration they don't get passed to
`onRecoverableError`. There's no global `onPostpone` API to capture
postponed things on the client just like there's no `onError`. At that
point it's just assumed to be intentional. It doesn't have any `digest`
or reason passed to the client since it's not logged.

There are some hacky solutions that currently just tries to reuse as
much of the existing code as possible but should be more properly
implemented.
- Fiber is currently just converting it to a fake Promise object so that
it behaves like an infinite Promise.
- Fizz is encoding the magic digest string `"POSTPONE"` in the HTML so
we know to ignore it but it should probably just be something neater
that doesn't share namespace with digests.

Next I plan on using this in the `/static` entry points for additional
features.

Why "postpone"? It's basically a synonym to "defer" but we plan on using
"defer" for other purposes and it's overloaded anyway.

DiffTrain build for [ac1a16c67e268fcb2c52e91717cbc918c7c24446](facebook/react@ac1a16c)

Author: jerrydev0927

compiled/facebook-www/REVISION

@@ -1 +1 @@
-0fb5b61ac6951a492242618e4ace6c1826335efc
+ac1a16c67e268fcb2c52e91717cbc918c7c24446

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

@@ -27,7 +27,7 @@ if (
 }
           "use strict";
 
-var ReactVersion = "18.3.0-www-modern-1d530573";
+var ReactVersion = "18.3.0-www-modern-00d6344c";
 
 // ATTENTION
 // When adding new symbols to this file,

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

@@ -615,4 +615,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactCurrentDispatcher.current.useTransition();
 };
-exports.version = "18.3.0-www-modern-8591a478";
+exports.version = "18.3.0-www-modern-5d9b9771";

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

@@ -9759,7 +9759,7 @@ var slice = Array.prototype.slice,
       return null;
     },
     bundleType: 0,
-    version: "18.3.0-www-modern-c25ea5bc",
+    version: "18.3.0-www-modern-0328f77f",
     rendererPackageName: "react-art"
   };
 var internals$jscomp$inline_1283 = {
@@ -9790,7 +9790,7 @@ var internals$jscomp$inline_1283 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-www-modern-c25ea5bc"
+  reconcilerVersion: "18.3.0-www-modern-0328f77f"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_1284 = __REACT_DEVTOOLS_GLOBAL_HOOK__;

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

@@ -10528,21 +10528,22 @@ function throwAndUnwindWorkLoop(unitOfWork, thrownValue) {
             renderDidSuspendDelayIfPossible();
             break a;
           } else value = Error(formatProdErrorMessage(426));
-        } else if (
-          isHydrating &&
-          unitOfWork.mode & 1 &&
-          ((wakeable = suspenseHandlerStackCursor.current), null !== wakeable)
-        ) {
-          0 === (wakeable.flags & 65536) && (wakeable.flags |= 256);
-          markSuspenseBoundaryShouldCapture(
-            wakeable,
-            returnFiber,
-            unitOfWork,
-            root,
-            thrownValue
-          );
-          queueHydrationError(createCapturedValueAtFiber(value, unitOfWork));
-          break a;
+        }
+        if (isHydrating && unitOfWork.mode & 1) {
+          var suspenseBoundary$61 = suspenseHandlerStackCursor.current;
+          if (null !== suspenseBoundary$61) {
+            0 === (suspenseBoundary$61.flags & 65536) &&
+              (suspenseBoundary$61.flags |= 256);
+            markSuspenseBoundaryShouldCapture(
+              suspenseBoundary$61,
+              returnFiber,
+              unitOfWork,
+              root,
+              thrownValue
+            );
+            queueHydrationError(createCapturedValueAtFiber(value, unitOfWork));
+            break a;
+          }
         }
         root = value = createCapturedValueAtFiber(value, unitOfWork);
         4 !== workInProgressRootExitStatus &&
@@ -16574,7 +16575,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1800 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "18.3.0-www-classic-ac0b40a5",
+  version: "18.3.0-www-classic-a80847ca",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2159 = {
@@ -16604,7 +16605,7 @@ var internals$jscomp$inline_2159 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-www-classic-ac0b40a5"
+  reconcilerVersion: "18.3.0-www-classic-a80847ca"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2160 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -16832,4 +16833,4 @@ exports.unstable_renderSubtreeIntoContainer = function (
   );
 };
 exports.unstable_runWithPriority = runWithPriority;
-exports.version = "18.3.0-www-classic-ac0b40a5";
+exports.version = "18.3.0-www-classic-a80847ca";

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

@@ -10360,21 +10360,22 @@ function throwAndUnwindWorkLoop(unitOfWork, thrownValue) {
             renderDidSuspendDelayIfPossible();
             break a;
           } else value = Error(formatProdErrorMessage(426));
-        } else if (
-          isHydrating &&
-          unitOfWork.mode & 1 &&
-          ((wakeable = suspenseHandlerStackCursor.current), null !== wakeable)
-        ) {
-          0 === (wakeable.flags & 65536) && (wakeable.flags |= 256);
-          markSuspenseBoundaryShouldCapture(
-            wakeable,
-            returnFiber,
-            unitOfWork,
-            root,
-            thrownValue
-          );
-          queueHydrationError(createCapturedValueAtFiber(value, unitOfWork));
-          break a;
+        }
+        if (isHydrating && unitOfWork.mode & 1) {
+          var suspenseBoundary$61 = suspenseHandlerStackCursor.current;
+          if (null !== suspenseBoundary$61) {
+            0 === (suspenseBoundary$61.flags & 65536) &&
+              (suspenseBoundary$61.flags |= 256);
+            markSuspenseBoundaryShouldCapture(
+              suspenseBoundary$61,
+              returnFiber,
+              unitOfWork,
+              root,
+              thrownValue
+            );
+            queueHydrationError(createCapturedValueAtFiber(value, unitOfWork));
+            break a;
+          }
         }
         root = value = createCapturedValueAtFiber(value, unitOfWork);
         4 !== workInProgressRootExitStatus &&
@@ -16104,7 +16105,7 @@ Internals.Events = [
 var devToolsConfig$jscomp$inline_1759 = {
   findFiberByHostInstance: getClosestInstanceFromNode,
   bundleType: 0,
-  version: "18.3.0-www-modern-c25ea5bc",
+  version: "18.3.0-www-modern-0328f77f",
   rendererPackageName: "react-dom"
 };
 var internals$jscomp$inline_2123 = {
@@ -16135,7 +16136,7 @@ var internals$jscomp$inline_2123 = {
   scheduleRoot: null,
   setRefreshHandler: null,
   getCurrentFiber: null,
-  reconcilerVersion: "18.3.0-www-modern-c25ea5bc"
+  reconcilerVersion: "18.3.0-www-modern-0328f77f"
 };
 if ("undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__) {
   var hook$jscomp$inline_2124 = __REACT_DEVTOOLS_GLOBAL_HOOK__;
@@ -16291,4 +16292,4 @@ exports.unstable_createEventHandle = function (type, options) {
   return eventHandle;
 };
 exports.unstable_runWithPriority = runWithPriority;
-exports.version = "18.3.0-www-modern-c25ea5bc";
+exports.version = "18.3.0-www-modern-0328f77f";