WIP [esnext] implement async iteration proposal

src/ast/ast-numbering.cc

Index: src/ast/ast-numbering.cc
diff --git a/src/ast/ast-numbering.cc b/src/ast/ast-numbering.cc
index 64e280a7bdf14033d3e5985fd5d474203b477774..571f023746554caf2e65e6cadb81cdb7628492a7 100644
--- a/src/ast/ast-numbering.cc
+++ b/src/ast/ast-numbering.cc
@@ -289,6 +289,13 @@ void AstNumberingVisitor::VisitCallRuntime(CallRuntime* node) {
       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);
+  }
 }