[turbofan] Eliminate checkpoints before return in common op reducer.

src/compiler/checkpoint-elimination.cc

Index: src/compiler/checkpoint-elimination.cc
diff --git a/src/compiler/checkpoint-elimination.cc b/src/compiler/checkpoint-elimination.cc
index 51ef9459e246c5fbd58634d083c035cc881da861..d44dfdff489e63a8f51d80c8816eee62524e696f 100644
--- a/src/compiler/checkpoint-elimination.cc
+++ b/src/compiler/checkpoint-elimination.cc
@@ -38,25 +38,10 @@ Reduction CheckpointElimination::ReduceCheckpoint(Node* node) {
   return NoChange();
 }
 
-Reduction CheckpointElimination::ReduceReturn(Node* node) {
-  DCHECK_EQ(IrOpcode::kReturn, node->opcode());
-  Node* effect = NodeProperties::GetEffectInput(node);
-  if (effect->opcode() == IrOpcode::kCheckpoint) {
-    // Any {Return} node can never be used to insert a deoptimization point,
-    // hence checkpoints can be cut out of the effect chain flowing into it.
-    Node* replacement = NodeProperties::GetEffectInput(effect);
-    NodeProperties::ReplaceEffectInput(node, replacement);
-    return Changed(node);
-  }
-  return NoChange();
-}
-
 Reduction CheckpointElimination::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kCheckpoint:
       return ReduceCheckpoint(node);
-    case IrOpcode::kReturn:
-      return ReduceReturn(node);
     default:
       break;
   }