[turbofan] Fix a flipped condition in JSGenericLowering

This fixes a serious performance regression in Octane2 future variant.

Bug: v8:7790
Change-Id: Ie72d7b8ecf8af12e06a0ecae216cfb456908fe5d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763542
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Auto-Submit: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63333}

src/compiler/js-generic-lowering.cc

@@ -157,9 +157,9 @@ bool ShouldUseMegamorphicLoadBuiltin(VectorSlotPair const& vector_slot_pair,
       broker->GetFeedback(FeedbackSource(vector_slot_pair));
 
   if (feedback.kind() == ProcessedFeedback::kElementAccess) {
-    return !feedback.AsElementAccess().transition_groups().empty();
+    return feedback.AsElementAccess().transition_groups().empty();
   } else if (feedback.kind() == ProcessedFeedback::kNamedAccess) {
-    return !feedback.AsNamedAccess().maps().empty();
+    return feedback.AsNamedAccess().maps().empty();
   } else if (feedback.kind() == ProcessedFeedback::kInsufficient) {
     return false;
   }