llvm-project

f6fc5e83 - [libc++][test] Guard non-guaranteed implicit-lifetime-ness cases with `_LIBCPP_VERSION` (#160627)

[libc++][test] Guard non-guaranteed implicit-lifetime-ness cases with `_LIBCPP_VERSION` (#160627) And add some guaranteed cases (namely, for `expected`, `optional`, and `variant`) to `is_implicit_lifetime.pass.cpp`. It's somehow unfortunate that `pair` and `tuple` are not guaranteed to propagate triviality of copy/move constructors, and MSVC STL fails to do so due to ABI compatibility. This affects the implicit-lifetime property.