Move generator-close on exception from the generator function to the GeneratorResume builtin.

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index c94f5785d2236bb5b763e7d20dfa63dc4d44ee15..e5622ab80917228a55494f92f31b95d745b48c68 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -1076,6 +1076,10 @@ class PreParser : public ParserBase<PreParser> {
       int pos, FunctionKind kind, PreParserStatementList body, bool* ok) {
     ParseStatementList(body, Token::RBRACE, ok);
   }
+  V8_INLINE void ParseAndRewriteAsyncGeneratorFunctionBody(
+      int pos, FunctionKind kind, PreParserStatementList body, bool* ok) {
+    ParseStatementList(body, Token::RBRACE, ok);
+  }
   V8_INLINE void CreateFunctionNameAssignment(
       PreParserIdentifier function_name, int pos,
       FunctionLiteral::FunctionType function_type,
@@ -1289,11 +1293,6 @@ class PreParser : public ParserBase<PreParser> {
     return PreParserExpression::Default();
   }
 
-  V8_INLINE PreParserExpression BuildIteratorResult(PreParserExpression value,
-                                                    bool done) {
-    return PreParserExpression::Default();
-  }
-
   V8_INLINE PreParserStatement
   BuildInitializationBlock(DeclarationParsingResult* parsing_result,
                            ZoneList<const AstRawString*>* names, bool* ok) {