ndk: remove undefined symbols from system headers

This change removes the declaration of functions that are not
implemented by our various versions of our C library.

The corresponding declarations are moved inside #if 0 .. #endif
blocks (so it becomes easy to remember that they are missing)

Also refresh the headers a little (i.e. adding a few missing decl
and macros, remove C++ comments, etc)

See http://code.google.com/p/android/issues/detail?id=7807

Change-Id: I4ae1b1f3a181419eee2004c41b54768cc15e896f
NOTE: The missing decl are still there but encased in #if 0 .. #endif
      blocks (to make it easier to implement them later). There are
      a few exceptions in order to build STLport and libstdc++-v3
      properly.
33 files changed