Stop RCTIdentifierPool::dequeue from spinning forever when the pool is full

dequeue() scanned for a free identifier in an unbounded loop. Once every
identifier was taken, which happens when the touch handlers leak them over
a long-lived process, the loop never exited and hung the main thread.

Bound the scan to one pass over the pool. If no identifier is free, reclaim
them all and reuse one. Also initialise lastIndex, which was read before
being assigned.

Fixes #58441

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: kimseongchan0914

packages/react-native/React/Fabric/Utils/RCTIdentifierPool.h

@@ -21,13 +21,20 @@ class RCTIdentifierPool {
 
   int dequeue()
   {
-    while (true) {
+    for (size_t attempt = 0; attempt < size; attempt++) {
       if (!usage[lastIndex]) {
         usage[lastIndex] = true;
         return lastIndex;
       }
       lastIndex = (lastIndex + 1) % size;
     }
+
+    // Every identifier is taken, which only happens when identifiers were leaked.
+    // Reclaim them all instead of scanning forever: a reused identifier is a
+    // transient glitch, while an endless loop here hangs the main thread.
+    usage.reset();
+    usage[lastIndex] = true;
+    return lastIndex;
   }
 
   void reset()
@@ -39,7 +46,7 @@ class RCTIdentifierPool {
 
  private:
   std::bitset<size> usage;
-  int lastIndex;
+  int lastIndex{0};
 };
 
 } // namespace facebook::react