PR libstdc++/79075
	* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI] (basic_string):
	Make _If_sv private.
	[!_GLIBCXX_USE_CXX11_ABI] (basic_string): Add member functions taking
	basic_string_view arguments.

From-SVN: r244445