WIP [esnext] implement async iteration proposal

src/ast/ast-numbering.cc

 // Copyright 2012 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/ast/ast-numbering.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/objects-inl.h"
 
@@ skipping 271 matching lines @@
   // The AstNumberingVisitor is what learns whether it is caught. To make
   // the information available later to the runtime, the AstNumberingVisitor
   // has to stash it somewhere. Changing the runtime function into another
   // one in ast-numbering seemed like a simple and straightforward solution to
   // that problem.
   if (node->is_jsruntime() &&
       node->context_index() == Context::ASYNC_FUNCTION_AWAIT_CAUGHT_INDEX &&
       catch_prediction_ == HandlerTable::ASYNC_AWAIT) {
     node->set_context_index(Context::ASYNC_FUNCTION_AWAIT_UNCAUGHT_INDEX);
   }
+
+  // Similar measures are taken for AsyncGeneratorAwait calls.
+  if (node->is_jsruntime() &&
+      node->context_index() == Context::ASYNC_GENERATOR_AWAIT_CAUGHT &&
+      catch_prediction_ == HandlerTable::ASYNC_AWAIT) {
+    node->set_context_index(Context::ASYNC_GENERATOR_AWAIT_UNCAUGHT);
+  }
 }
 
 
 void AstNumberingVisitor::VisitWithStatement(WithStatement* node) {
   IncrementNodeCount();
   DisableFullCodegenAndCrankshaft(kWithStatement);
   Visit(node->expression());
   Visit(node->statement());
 }
 
@@ skipping 350 matching lines @@
 }
 
 
 bool AstNumbering::Renumber(Isolate* isolate, Zone* zone,
                             FunctionLiteral* function) {
   AstNumberingVisitor visitor(isolate, zone);
   return visitor.Renumber(function);
 }
 }  // namespace internal
 }  // namespace v8