[turbofan] Change End to take a variable number of inputs.

src/compiler/node-properties.cc

Index: src/compiler/node-properties.cc
diff --git a/src/compiler/node-properties.cc b/src/compiler/node-properties.cc
index 9e665d10e992087229cfca18bcb96bd9ace8bad8..0aeea93161e1aa814b56edb95dc6257bd023ba1a 100644
--- a/src/compiler/node-properties.cc
+++ b/src/compiler/node-properties.cc
@@ -163,16 +163,8 @@ void NodeProperties::RemoveNonValueInputs(Node* node) {
 void NodeProperties::MergeControlToEnd(Graph* graph,
                                        CommonOperatorBuilder* common,
                                        Node* node) {
-  // Connect the node to the merge exiting the graph.
-  Node* end_pred = NodeProperties::GetControlInput(graph->end());
-  if (end_pred->opcode() == IrOpcode::kMerge) {
-    int inputs = end_pred->op()->ControlInputCount() + 1;
-    end_pred->AppendInput(graph->zone(), node);
-    end_pred->set_op(common->Merge(inputs));
-  } else {
-    Node* merge = graph->NewNode(common->Merge(2), end_pred, node);
-    NodeProperties::ReplaceControlInput(graph->end(), merge);
-  }
+  graph->end()->AppendInput(graph->zone(), node);
+  graph->end()->set_op(common->End(graph->end()->InputCount()));
 }