[turbofan] Support variable size argument popping in TF-generated functions

test/unittests/compiler/loop-peeling-unittest.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/loop-peeling.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 72 matching lines @@
     PeeledIteration* peeled =
         LoopPeeler::Peel(graph(), common(), loop_tree, loop, zone());
     if (FLAG_trace_turbo_graph) {
       OFStream os(stdout);
       os << AsRPO(*graph());
     }
     return peeled;
   }
 
   Node* InsertReturn(Node* val, Node* effect, Node* control) {
-    Node* r = graph()->NewNode(common()->Return(), val, effect, control);
+    Node* zero = graph()->NewNode(common()->Int32Constant(0));
+    Node* r = graph()->NewNode(common()->Return(), zero, val, effect, control);
     graph()->SetEnd(r);
     return r;
   }
 
   Node* ExpectPeeled(Node* node, PeeledIteration* iter) {
     Node* p = iter->map(node);
     EXPECT_NE(node, p);
     return p;
   }
 
@@ skipping 413 matching lines @@
     LoopTree* loop_tree = GetLoopTree();
     LoopTree::Loop* loop = loop_tree->outer_loops()[0];
     EXPECT_FALSE(LoopPeeler::CanPeel(loop_tree, loop));
   }
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8