locale_facets.tcc (num_put::_M_convert_float): Allow one more digit of precision.

2002-03-08  scott snyder  <snyder@fnal.gov>

	libstdc++/5875
	* include/bits/locale_facets.tcc (num_put::_M_convert_float):
	Allow one more digit of precision.
	* testsuite/27_io/ostream_inserter_arith.cc: Test that we can

From-SVN: r50471