2013-09-24  Marc Glisse  <marc.glisse@inria.fr>

	PR libstdc++/58338
	PR libstdc++/56166
	* include/bits/basic_string.h (basic_string)
	[basic_string(basic_string&&)]: Make the noexcept conditional.
	[operator=(basic_string&&), assign(basic_string&&)]: Link to PR 58265.
	[begin(), end(), rbegin(), rend(), clear]: Remove noexcept.
	[pop_back]: Comment on the lack of noexcept.
	* include/debug/string (basic_string) [basic_string(const _Allocator&),
	basic_string(basic_string&&), begin(), end(), rbegin(), rend(), clear,
	operator[](size_type), pop_back]: Comment out noexcept, until vstring
	replaces basic_string.

From-SVN: r202861