PR libstdc++/81256
	* include/bits/fstream.tcc (basic_filebuf::close): Do not swallow
	exceptions from _M_terminate_output().
	* include/std/fstream (basic_filebuf::~basic_filebuf): Swallow any
	exceptions from close().
	* testsuite/27_io/basic_filebuf/close/81256.cc: New.

From-SVN: r260236