std_streambuf.h: Remove cached locale facets.

2001-03-14  Benjamin Kosnik  <bkoz@redhat.com>

	libstdc++/2020
	* include/bits/std_streambuf.h: Remove cached locale facets.
	(basic_streambuf::_M_buf_fctype): Remove.
	(basic_streambuf::~basic_streambuf): Remove here.
	(basic_streambuf::basic_streambuf): Same.
	(basic_streambuf::imbue): Same.
	* include/bits/fstream.tcc (filebuf::imbue): Remove _M_buf_fctype.
	* include/bits/std_fstream.h (basic_filebuf::_M_fcvt): Remove.
	(basic_filebuf::~basic_filebuf()): Remove here.
	* include/bits/fstream.tcc (basic_filebuf::basic_filebuf): Same.
	(basic_filebuf::imbue): Same.
	* include/bits/localefwd.h (_Count_ones): Remove.
	(locale::_S_num_categories): Just use 6, since this doesn't
	actually change, ever.
	* include/bits/locale_facets.tcc (has_facet): Simplify.
	(use_facet): Same.
	* testsuite/27_io/filebuf.cc (test06): Add tests.

From-SVN: r40472