Experimental scanner: initialize starting position in literal descriptor.

src/lexer/experimental-scanner.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 234 matching lines @@
     bool has_escapes;
   };
 
   struct LiteralDesc {
     int beg_pos;
     bool is_ascii;
     int length;
     Vector<const char> ascii_string;
     Vector<const uc16> utf16_string;
     LiteralBuffer buffer;
+    LiteralDesc() : beg_pos(-1), is_ascii(false), length(0) { }
     bool Valid(int pos) { return beg_pos == pos; }
   };
 
   virtual void Scan() = 0;
   virtual void SetBufferBasedOnHandle() = 0;
 
   static void UpdateBuffersAfterGC(v8::Isolate*, GCType, GCCallbackFlags);
   virtual bool FillLiteral(const TokenDesc& token, LiteralDesc* literal) = 0;
 
   Isolate* isolate_;
@@ skipping 338 matching lines @@
   // character.
   const Char* temp_cursor = last_octal_end_ - 1;
   while (temp_cursor >= buffer_ && *temp_cursor >= '0' && *temp_cursor <= '7')
     --temp_cursor;
   return Location(temp_cursor - buffer_ + 1, last_octal_end_ - buffer_);
 }
 
 } }
 
 #endif  // V8_LEXER_EXPERIMENTAL_SCANNER_H