PR libstdc++/68323
	PR libstdc++/77794
	* config/abi/pre/gnu-versioned-namespace.ver: Add exports for
	__cxa_thread_atexit and __gnu_cxx::__freeres.
	* include/Makefile.am: Add <experimental/bits/lfts_config.h>
	* include/Makefile.in: Regenerate.
	* include.bits/basic_string.h: Fix nesting of versioned namespaces.
	* include/bits/c++config: Declare versioned namespaces for literals.
	* include/bits/regex.h (basic_regex, match_results): Add workarounds
	for PR c++/59256.
	* include/bits/uniform_int_dist.h: Fix nesting of versioned namespace.
	* include/std/chrono: Likewise.
	* include/std/complex: Likewise.
	* include/std/string_view: Likewise.
	* include/std/variant: Likewise. Add workaround for PR c++/59256.
	* include/experimental/bits/fs_fwd.h: Declare versioned namespace.
	* include/experimental/bits/lfts_config.h: Declare versioned
	namespaces.
	* include/experimental/algorithm: Include
	<experimental/bits/lfts_config.h>.
	* include/experimental/any: Likewise.
	* include/experimental/bits/erase_if.h: Likewise.
	* include/experimental/chrono: Likewise.
	* include/experimental/functional: Likewise.
	* include/experimental/memory_resource: Likewise.
	* include/experimental/optional: Likewise.
	* include/experimental/propagate_const: Likewise.
	* include/experimental/random: Likewise.
	* include/experimental/ratio: Likewise.
	* include/experimental/system_error: Likewise.
	* include/experimental/tuple: Likewise.
	* include/experimental/type_traits: Likewise.
	* include/experimental/utility: Likewise.
	* include/experimental/string_view: Likewise. Fix nesting of
	versioned namespaces.
	* include/experimental/bits/string_view.tcc: Reopen inline namespace
	for non-inline function definitions.
	* testsuite/17_intro/using_namespace_std_exp_neg.cc: New test.
	* testsuite/20_util/duration/literals/range.cc: Adjust dg-error line.
	* testsuite/experimental/any/misc/any_cast_neg.cc: Likewise.
	* testsuite/experimental/propagate_const/assignment/move_neg.cc:
	Likewise.
	* testsuite/experimental/propagate_const/cons/move_neg.cc: Likewise.
	* testsuite/experimental/propagate_const/requirements2.cc: Likewise.
	* testsuite/experimental/propagate_const/requirements3.cc: Likewise.
	* testsuite/experimental/propagate_const/requirements4.cc: Likewise.
	* testsuite/experimental/propagate_const/requirements5.cc: Likewise.
	* testsuite/ext/profile/mutex_extensions_neg.cc: Likewise.

From-SVN: r240714