Move traverseFragmentInstanceChildren to internal ReactFiberTreeReflection (#32613)

This is a nit but a Config should not have to know anything about the
internals of Fibers. Ideally it shouldn't even access them but we have
some cases where we need pointers back in like for this fragment.

The way we've typically abstracted this is using the
`ReactFiberTreeReflection` helper that's in the `react-reconciler`. Such
as in the event system.
https://github.com/facebook/react/blob/f3c956006a90dc68210bd3e19497d10fb9b028d3/packages/react-dom-bindings/src/events/ReactDOMEventListener.js#L22-L26

We sometimes cheat but we really should clean this up such that a
`Fiber` is actually an opaque type to the Configs and it can never dot
into it without using a helper.

So this just moves `traverseFragmentInstanceChildren` to
ReactFiberTreeReflection so that the ConfigDOM doesn't ever dot into its
fields itself. It just passes the Fiber through back into the
react-reconciler. I had to add a wrapper to read the `.child` to avoid
that being assumed too. I also noticed that FragmentInstanceType is not
actually passed through so that argument is unnecessary.

DiffTrain build for [6b5d9fd](6b5d9fd)

Author: sebmarkbage

compiled/facebook-www/REVISION

@@ -1 +1 @@
-2c560374d6276c51cfeeff7af39628058c155a13
+17d274dc127400b31379a1b26c5be53599c36aa5

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-2c560374d6276c51cfeeff7af39628058c155a13
+17d274dc127400b31379a1b26c5be53599c36aa5

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

@@ -1532,7 +1532,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.1.0-www-classic-2c560374-20250314";
+    exports.version = "19.1.0-www-classic-6b5d9fd3-20250314";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -1532,7 +1532,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.1.0-www-modern-2c560374-20250314";
+    exports.version = "19.1.0-www-modern-6b5d9fd3-20250314";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -641,4 +641,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.1.0-www-classic-2c560374-20250314";
+exports.version = "19.1.0-www-classic-6b5d9fd3-20250314";

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

@@ -641,4 +641,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.1.0-www-modern-2c560374-20250314";
+exports.version = "19.1.0-www-modern-6b5d9fd3-20250314";

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

@@ -645,7 +645,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.1.0-www-classic-2c560374-20250314";
+exports.version = "19.1.0-www-classic-6b5d9fd3-20250314";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -645,7 +645,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.1.0-www-modern-2c560374-20250314";
+exports.version = "19.1.0-www-modern-6b5d9fd3-20250314";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -18507,10 +18507,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.1.0-www-classic-2c560374-20250314",
+        version: "19.1.0-www-classic-6b5d9fd3-20250314",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.1.0-www-classic-2c560374-20250314"
+        reconcilerVersion: "19.1.0-www-classic-6b5d9fd3-20250314"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -18544,7 +18544,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.1.0-www-classic-2c560374-20250314";
+    exports.version = "19.1.0-www-classic-6b5d9fd3-20250314";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

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

@@ -18279,10 +18279,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.1.0-www-modern-2c560374-20250314",
+        version: "19.1.0-www-modern-6b5d9fd3-20250314",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.1.0-www-modern-2c560374-20250314"
+        reconcilerVersion: "19.1.0-www-modern-6b5d9fd3-20250314"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -18316,7 +18316,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.1.0-www-modern-2c560374-20250314";
+    exports.version = "19.1.0-www-modern-6b5d9fd3-20250314";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&