WIP [esnext] implement async iteration proposal

src/compiler/machine-graph-verifier.cc

 // Copyright 2016 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/machine-graph-verifier.h"
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 501 matching lines @@
                   CheckValueInputRepresentationIs(
                       node, 2, inferrer_->GetRepresentation(node));
               }
               break;
             }
             break;
           }
           case IrOpcode::kTypedStateValues:
           case IrOpcode::kFrameState:
             break;
+          case IrOpcode::kRetain:

[caitp, 2017/01/10 04:13:41]

TODO(caitp): get rid of this (and any calls to Retain() added in CSA builtins in
this patch, they didn't really solve any GC issues I was debugging previously)

+            break;
           default:
             if (node->op()->ValueInputCount() != 0) {
               std::stringstream str;
               str << "Node #" << node->id() << ":" << *node->op()
                   << " in the machine graph is not being checked.";
               PrintDebugHelp(str, node);
               FATAL(str.str().c_str());
             }
             break;
         }
@@ skipping 269 matching lines @@
   MachineRepresentationInferrer representation_inferrer(schedule, graph,
                                                         linkage, temp_zone);
   MachineRepresentationChecker checker(schedule, &representation_inferrer,
                                        is_stub, name);
   checker.Run();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8