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

base/preprocessor_fun.h

-// Copyright 2005-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-// PP_STRINGIZE - expands arguments before stringizing
-// PP_STRINGIZE(PP_CAT(a,b)) => "ab"
-
-#define PP_STRINGIZE(text)   PP_STRINGIZE_A((text))
-#define PP_STRINGIZE_A(arg)  PP_STRINGIZE_B ## (arg)
-#define PP_STRINGIZE_B(arg)  PP_STRINGIZE_I ## arg
-#define PP_STRINGIZE_I(text) #text
-
-// T_PP_STRINGIZE - expands arguments before stringizing
-// T_PP_STRINGIZE(PP_CAT(a,b)) => _T("ab")
-
-#define T_PP_STRINGIZE(text)   T_PP_STRINGIZE_A((text))
-#define T_PP_STRINGIZE_A(arg)  T_PP_STRINGIZE_B ## (arg)
-#define T_PP_STRINGIZE_B(arg)  T_PP_STRINGIZE_I ## arg
-#define T_PP_STRINGIZE_I(text) _T(#text)
-
-// PP_CAT - concatenates arguments after they have been expanded
-// PP_CAT(x, PP_CAT(y,z)) => xyz
-#define PP_CAT(a,b)   PP_CAT_I(a,b)
-#define PP_CAT_I(a,b) PP_CAT_J(a##b)
-#define PP_CAT_J(arg) arg