Keep two empty lines between declarations for cpp files

src/bignum.cc

 // Copyright 2011 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 27 matching lines @@
     bigits_[i] = 0;
   }
 }
 
 
 template<typename S>
 static int BitSize(S value) {
   return 8 * sizeof(value);
 }
 
+
 // Guaranteed to lie in one Bigit.
 void Bignum::AssignUInt16(uint16_t value) {
   ASSERT(kBigitSize >= BitSize(value));
   Zero();
   if (value == 0) return;
 
   EnsureCapacity(1);
   bigits_[0] = value;
   used_digits_ = 1;
 }
@@ skipping 707 matching lines @@
     Chunk difference = bigits_[i] - borrow;
     bigits_[i] = difference & kBigitMask;
     borrow = difference >> (kChunkSize - 1);
   }
   Clamp();
   ASSERT(Bignum::Equal(a, *this));
 }
 
 
 } }  // namespace v8::internal