Reland "[parser] Forbid \08 in strict strings"

src/parsing/scanner.cc

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/parsing/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 1014 matching lines @@
     int nx = x * 8 + d;
     if (nx >= 256) break;
     x = nx;
     Advance<capture_raw>();
   }
   // Anything except '\0' is an octal escape sequence, illegal in strict mode.
   // Remember the position of octal escape sequences so that an error
   // can be reported later (in strict mode).
   // We don't report the error immediately, because the octal escape can
   // occur before the "use strict" directive.
-  if (c != '0' || i > 0) {
+  if (c != '0' || i > 0 || c0_ == '8' || c0_ == '9') {
     octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
     octal_message_ = MessageTemplate::kStrictOctalEscape;
   }
   return x;
 }
 
 
 Token::Value Scanner::ScanString() {
   uc32 quote = c0_;
   Advance<false, false>();  // consume quote
@@ skipping 761 matching lines @@
   // 2, reset the source to the desired position,
   source_->Seek(position);
   // 3, re-scan, by scanning the look-ahead char + 1 token (next_).
   c0_ = source_->Advance();
   Next();
   DCHECK_EQ(next_.location.beg_pos, static_cast<int>(position));
 }
 
 }  // namespace internal
 }  // namespace v8