Don't create empty vectors using SubVector.

src/strtod.cc

 // Copyright 2010 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 110 matching lines @@
   return gay_strtod(gay_buffer, NULL);
 }
 
 
 static Vector<const char> TrimLeadingZeros(Vector<const char> buffer) {
   for (int i = 0; i < buffer.length(); i++) {
     if (buffer[i] != '0') {
       return buffer.SubVector(i, buffer.length());
     }
   }
-  return buffer.SubVector(0, 0);
+  return Vector<const char>(buffer.start(), 0);
 }
 
 
 static Vector<const char> TrimTrailingZeros(Vector<const char> buffer) {
   for (int i = buffer.length() - 1; i >= 0; --i) {
     if (buffer[i] != '0') {
       return buffer.SubVector(0, i + 1);
     }
   }
-  return buffer.SubVector(0, 0);
+  return Vector<const char>(buffer.start(), 0);
 }
 
 
 // Reads digits from the buffer and converts them to a uint64.
 // Reads in as many digits as fit into a uint64.
 // When the string starts with "1844674407370955161" no further digit is read.
 // Since 2^64 = 18446744073709551616 it would still be possible read another
 // digit if it was less or equal than 6, but this would complicate the code.
 static uint64_t ReadUint64(Vector<const char> buffer,
                            int* number_of_read_digits) {
@@ skipping 232 matching lines @@
 
   double result;
   if (DoubleStrtod(trimmed, exponent, &result) ||
       DiyFpStrtod(trimmed, exponent, &result)) {
     return result;
   }
   return old_strtod(trimmed, exponent);
 }
 
 } }  // namespace v8::internal