istream.cc (basic_istream<char>::ignore(streamsize), [...]): Avoid _M_gcount overflows.

2005-01-02  Paolo Carlini  <pcarlini@suse.de>

	* src/istream.cc (basic_istream<char>::ignore(streamsize),
	basic_istream<char>::ignore(streamsize, int_type),
	basic_istream<wchar_t>::ignore(streamsize),
	basic_istream<wchar_t>::ignore(streamsize, int_type)): Avoid
	_M_gcount overflows.
	* include/bits/istream.tcc (ignore(streamsize), ignore(streamsize,
	int_type)): Likewise; use snextc in the main loop, consistently
	with the specializations above.

From-SVN: r92816