Created collector class and used it to collect identifiers during scanning.

src/conversions.cc

 // Copyright 2006-2008 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 715 matching lines @@
     StringInputBuffer buffer(str);
     return InternalStringToInt(StringInputBufferIterator(&buffer),
                                StringInputBufferIterator::EndMarker(),
                                radix);
   }
 }
 
 
 double StringToDouble(const char* str, int flags, double empty_string_val) {
   const char* end = str + StrLength(str);
+  return InternalStringToDouble(str, end, flags, empty_string_val);
+}
 
-  return InternalStringToDouble(str, end, flags, empty_string_val);
+
+double StringToDouble(Vector<const char> str,
+                      int flags,
+                      double empty_string_val) {
+  const char* end = str.start() + str.length();
+  return InternalStringToDouble(str.start(), end, flags, empty_string_val);
 }
 
 
 extern "C" char* dtoa(double d, int mode, int ndigits,
                       int* decpt, int* sign, char** rve);
 
 extern "C" void freedtoa(char* s);
 
 const char* DoubleToCString(double v, Vector<char> buffer) {
   StringBuilder builder(buffer.start(), buffer.length());
@@ skipping 362 matching lines @@
   // Allocate result and fill in the parts.
   StringBuilder builder(result_size + 1);
   builder.AddSubstring(integer_buffer + integer_pos + 1, integer_part_size);
   if (decimal_pos > 0) builder.AddCharacter('.');
   builder.AddSubstring(decimal_buffer, decimal_pos);
   return builder.Finalize();
 }
 
 
 } }  // namespace v8::internal