[compiler] enablePreserveMemo treats manual deps as non-nullable (#34503)

The `@enablePreserveExistingMemoizationGuarantees` mode can still fail
to preserve manual memoization due to mismtached dependencies.
Specifically, where the user's dependencies are more precise than the
compiler infers bc the compiler is being conservative about what might
be nullable. In this mode though we're intentionally using information
from the manual memoization and can also rely on the deps as a signal
for what's non-nullable.

The idea of the PR is that we treat manual memo deps just like other
inferred-as-non-nullable objects during PropagateScopeDeps. We're
careful to not treat the full path as non-nullable, only up to the last
property index. So `x.y.z` as a manual dep treats `x` and `x.y` as
non-nullable, allowing us to preserve a conditional dependency on
`x.y.z`.

Optionals within manual dependencies are a bit trickier and aren't
handled yet, but hopefully that's less common and something we can
improve in a follow-up. Not handling them just means that developers may
hit false positives on validating existing memoization if they use
optional chains in manual dependencies.

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34503).
* #34689
* __->__ #34503

DiffTrain build for [57d5a59](57d5a59)

Author: josephsavona

compiled/eslint-plugin-react-hooks/index.js

@@ -45363,6 +45363,29 @@ function collectNonNullsInBlocks(fn, context) {
                     }
                 }
             }
+            else if (fn.env.config.enablePreserveExistingMemoizationGuarantees &&
+                instr.value.kind === 'StartMemoize' &&
+                instr.value.deps != null) {
+                for (const dep of instr.value.deps) {
+                    if (dep.root.kind === 'NamedLocal') {
+                        if (!isImmutableAtInstr(dep.root.value.identifier, instr.id, context)) {
+                            continue;
+                        }
+                        for (let i = 0; i < dep.path.length; i++) {
+                            const pathEntry = dep.path[i];
+                            if (pathEntry.optional) {
+                                break;
+                            }
+                            const depNode = context.registry.getOrCreateProperty({
+                                identifier: dep.root.value.identifier,
+                                path: dep.path.slice(0, i),
+                                reactive: dep.root.value.reactive,
+                            });
+                            assumedNonNullObjects.add(depNode);
+                        }
+                    }
+                }
+            }
         }
         nodes.set(block.id, {
             block,

compiled/facebook-www/REVISION

@@ -1 +1 @@
-d74f061b6908e4841b2eb09c296ca4658dbdd38e
+57d5a59748bbec1b507bb778c9fbe4bcb82b0a94

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-d74f061b6908e4841b2eb09c296ca4658dbdd38e
+57d5a59748bbec1b507bb778c9fbe4bcb82b0a94

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

@@ -1458,7 +1458,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.3.0-www-classic-d74f061b-20251001";
+    exports.version = "19.3.0-www-classic-57d5a597-20251002";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -1458,7 +1458,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.3.0-www-modern-d74f061b-20251001";
+    exports.version = "19.3.0-www-modern-57d5a597-20251002";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -604,4 +604,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-classic-d74f061b-20251001";
+exports.version = "19.3.0-www-classic-57d5a597-20251002";

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

@@ -604,4 +604,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-modern-d74f061b-20251001";
+exports.version = "19.3.0-www-modern-57d5a597-20251002";

compiled/facebook-www/React-profiling.classic.js

@@ -608,7 +608,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-classic-d74f061b-20251001";
+exports.version = "19.3.0-www-classic-57d5a597-20251002";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -608,7 +608,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.3.0-www-modern-d74f061b-20251001";
+exports.version = "19.3.0-www-modern-57d5a597-20251002";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -20303,10 +20303,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.3.0-www-classic-d74f061b-20251001",
+        version: "19.3.0-www-classic-57d5a597-20251002",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.3.0-www-classic-d74f061b-20251001"
+        reconcilerVersion: "19.3.0-www-classic-57d5a597-20251002"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -20341,7 +20341,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.3.0-www-classic-d74f061b-20251001";
+    exports.version = "19.3.0-www-classic-57d5a597-20251002";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&