On the 'cmake' branch: Update CMakeLists.txt the same way as r1920521 updates
extractor.py in /trunk (merged to this branch in r1920671).

Refer to the authorative explanation why we use CONSTANT and not DATA, even
though it causes an LNK4087 warning!

* CMakeLists.txt
  (target_exports): Just a comment

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/cmake@1920672 13f79535-47bb-0310-9956-ffa450edef68