WIP [esnext] implement async iteration proposal

src/interpreter/bytecode-generator.h

Index: src/interpreter/bytecode-generator.h
diff --git a/src/interpreter/bytecode-generator.h b/src/interpreter/bytecode-generator.h
index ed1187de846ddfe7f90db7475d481043eddd5bf2..dd739f151970a735f675241dff8c3282c558394a 100644
--- a/src/interpreter/bytecode-generator.h
+++ b/src/interpreter/bytecode-generator.h
@@ -197,6 +197,7 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   Handle<Name> home_object_symbol() const { return home_object_symbol_; }
   Handle<Name> iterator_symbol() const { return iterator_symbol_; }
+  Handle<Name> async_iterator_symbol() const { return async_iterator_symbol_; }
   Handle<Name> prototype_string() const { return prototype_string_; }
   Handle<FixedArray> empty_fixed_array() const { return empty_fixed_array_; }
   const AstRawString* undefined_string() const { return undefined_string_; }
@@ -223,6 +224,7 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
 
   Handle<Name> home_object_symbol_;
   Handle<Name> iterator_symbol_;
+  Handle<Name> async_iterator_symbol_;
   Handle<Name> prototype_string_;
   Handle<FixedArray> empty_fixed_array_;
   const AstRawString* undefined_string_;