[parser] Relax DCHECK in has_error() case

No-Tree-Checks: true
No-Try: true
Bug: chromium:908231
Change-Id: I1acf33400ad3546974a0ccb5955f8c6966b17dcf
Reviewed-on: https://chromium-review.googlesource.com/c/1350116
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57815}

src/parsing/parser.cc

@@ -2497,7 +2497,7 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
   // immediately). bar can be parsed lazily, but we need to parse it in a mode
   // that tracks unresolved variables.
   DCHECK_IMPLIES(parse_lazily(), FLAG_lazy);
-  DCHECK_IMPLIES(parse_lazily(), allow_lazy_);
+  DCHECK_IMPLIES(parse_lazily(), has_error() || allow_lazy_);
   DCHECK_IMPLIES(parse_lazily(), extension_ == nullptr);
 
   const bool is_lazy =

test/mjsunit/regress/regress-908231.js

+// Copyright 2018 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.
+
+assertThrows(`
+    class C {
+      get [(function() { function lazy() { Syntax Error } })()]() {}
+    }`, SyntaxError)