[scanner] Reset invalid_template_escape_message during Bookmark::Apply

Bug: chromium:905587
Change-Id: I168fdfd433edcda61dcefd0df9df8a12c5294339
Reviewed-on: https://chromium-review.googlesource.com/c/1340040
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57568}

src/parsing/scanner.cc

@@ -1168,7 +1168,10 @@ void Scanner::SeekNext(size_t position) {
   // 1, Reset the current_, next_ and next_next_ tokens
   //    (next_ + next_next_ will be overwrittem by Next(),
   //     current_ will remain unchanged, so overwrite it fully.)
-  for (TokenDesc& token : token_storage_) token.token = Token::UNINITIALIZED;
+  for (TokenDesc& token : token_storage_) {
+    token.token = Token::UNINITIALIZED;
+    token.invalid_template_escape_message = MessageTemplate::kNone;
+  }
   // 2, reset the source to the desired position,
   source_->Seek(position);
   // 3, re-scan, by scanning the look-ahead char + 1 token (next_).

test/mjsunit/regress/regress-905587.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("function test() { '\\u`''\\u' }", SyntaxError)