Add UseCounter for decimal with leading zero.

src/parsing/scanner.h

 // 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.
 
 #ifndef V8_PARSING_SCANNER_H_
 #define V8_PARSING_SCANNER_H_
 
 #include "src/allocation.h"
@@ skipping 407 matching lines @@
     }
   }
 
   int FindSymbol(DuplicateFinder* finder, int value);
 
   UnicodeCache* unicode_cache() { return unicode_cache_; }
 
   // Returns the location of the last seen octal literal.
   Location octal_position() const { return octal_pos_; }
   void clear_octal_position() { octal_pos_ = Location::invalid(); }
+  // Returns the location of the last seen decimal literal with a leading zero.
+  Location decimal_with_leading_zero_position() const {
+    return decimal_with_leading_zero_pos_;
+  }
+  void clear_decimal_with_leading_zero_position() {
+    decimal_with_leading_zero_pos_ = Location::invalid();
+  }
 
   // Returns the value of the last smi that was scanned.
   int smi_value() const { return current_.smi_value_; }
 
   // Seek forward to the given position.  This operation does not
   // work in general, for instance when there are pushed back
   // characters, but works for seeking forward until simple delimiter
   // tokens, which is what it is used for.
   void SeekForward(int pos);
 
@@ skipping 327 matching lines @@
   TokenDesc bookmark_current_;
   TokenDesc bookmark_next_;
   LiteralBuffer bookmark_current_literal_;
   LiteralBuffer bookmark_current_raw_literal_;
   LiteralBuffer bookmark_next_literal_;
   LiteralBuffer bookmark_next_raw_literal_;
 
   // Input stream. Must be initialized to an Utf16CharacterStream.
   Utf16CharacterStream* source_;
 
-
-  // Start position of the octal literal last scanned.
+  // Last-seen positions of potentially problematic tokens.
   Location octal_pos_;
+  Location decimal_with_leading_zero_pos_;
 
   // One Unicode character look-ahead; c0_ < 0 at the end of the input.
   uc32 c0_;
 
   // Whether there is a line terminator whitespace character after
   // the current token, and  before the next. Does not count newlines
   // inside multiline comments.
   bool has_line_terminator_before_next_;
   // Whether there is a multi-line comment that contains a
   // line-terminator after the current token, and before the next.
   bool has_multiline_comment_before_next_;
 
   // Whether this scanner encountered an HTML comment.
   bool found_html_comment_;
 
   bool allow_harmony_exponentiation_operator_;
 
   MessageTemplate::Template scanner_error_;
   Location scanner_error_location_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_SCANNER_H_