* include/bits/basic_string.h [!_GLIBCXX_USE_CXX11_ABI]
	(basic_string::front() const, basic_string::back() const): Use
	noexcept instead of _GLIBCXX_NOEXCEPT macro.
	(__versa_string::front, __versa_string::back): Likewise.

From-SVN: r228434