PR libstdc++/77322
	* doc/xml/manual/intro.xml: Document DR 2062 change.
	* include/std/functional (function::swap): Add noexcept.
	(swap(function<Res(Args...)&, function<Res(Args...)&)): Likewise.
	* testsuite/20_util/function/77322.cc: New test.

From-SVN: r239662