Keep only base/extractor.[cc|h].

third_party/lzma/v4_65/files/CPP/7zip/Compress/ByteSwap.cpp

-// ByteSwap.cpp
-
-#include "StdAfx.h"
-
-#include "ByteSwap.h"
-
-STDMETHODIMP CByteSwap2::Init() { return S_OK; }
-
-STDMETHODIMP_(UInt32) CByteSwap2::Filter(Byte *data, UInt32 size)
-{
-  const UInt32 kStep = 2;
-  UInt32 i;
-  for (i = 0; i + kStep <= size; i += kStep)
-  {
-    Byte b = data[i];
-    data[i] = data[i + 1];
-    data[i + 1] = b;
-  }
-  return i;
-}
-
-STDMETHODIMP CByteSwap4::Init() { return S_OK; }
-
-STDMETHODIMP_(UInt32) CByteSwap4::Filter(Byte *data, UInt32 size)
-{
-  const UInt32 kStep = 4;
-  UInt32 i;
-  for (i = 0; i + kStep <= size; i += kStep)
-  {
-    Byte b0 = data[i];
-    Byte b1 = data[i + 1];
-    data[i] = data[i + 3];
-    data[i + 1] = data[i + 2];
-    data[i + 2] = b1;
-    data[i + 3] = b0;
-  }
-  return i;
-}