re PR libstdc++/9339 (filebuf::pubsetbuf(0, 0) doesn't turn off buffering)

2003-05-26  Benjamin Kosnik  <bkoz@redhat.com>

	PR libstdc++/9339
	* include/std/std_fstream.h (basic_filebuf::_M_overflow): Remove.
	(_M_pback): No array necessary.
	* include/bits/fstream.tcc (basic_filebuf::_M_overflow): Add
	unbuffered case, coalesec into ...
	(basic_filebuf::overflow): ...this.
	* testsuite/27_io/basic_filebuf/sputn/char/9339.cc: New.
	* testsuite/27_io/basic_filebuf/sputc/char/2.cc: Unbuffered.

From-SVN: r67175