re PR libstdc++/47145 (configure test for docbook-xsl-ns stylesheets uses hardcoded path)

2011-01-04  Kai Tietz  <kai.tietz@onevision.com>

        PR libstdc++/47145
        * configure.ac (AC_CHECK_FILE): Replaced by test -f.
        * configure: Regenerated.

Unbreaking cross-compiling ...

From-SVN: r168474