[Bug target/65171] [5 Regression] r214254 causes thousands of std::length_errors running boost testsuite on ppc64le

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65171

--- Comment #3 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Problem is an invalid swap removal in:

bool boost::test_tools::tt_detail::report_assertion(const
boost::test_tools::as\
sertion_result&, const boost::unit_test::lazy_ostream&,
boost::unit_test::const\
_string, std::size_t, boost::test_tools::tt_detail::tool_level,
boost::test_too\
ls::tt_detail::check_type, std::size_t, ...)

Something going on with subreg handling.