Update on "[compiler][patch] Patch O(n^2) traversal in validatePreserveMemo"

Double checked by syncing internally and verifying the # of `visitInstruction` calls with unique `InstructionId`s.

This is a bit of an awkward pattern though. A cleaner alternative might be to override `visitValue` and store its results in a sidemap (instead of returning)

[ghstack-poisoned]

Author: mofeiZ

compiler/packages/babel-plugin-react-compiler/src/HIR/PruneUnusedLabelsHIR.ts

@@ -69,7 +69,7 @@ export function pruneUnusedLabelsHIR(fn: HIRFunction): void {
   }
 
   for (const [_, block] of fn.body.blocks) {
-    for (const pred of [...block.preds]) {
+    for (const pred of block.preds) {
       const rewritten = rewrites.get(pred);
       if (rewritten != null) {
         block.preds.delete(pred);