16087eeea8
the unadjusted ABI needs to pass aggregates by-value Fixes https://github.com/rust-lang/rust/issues/118124, a regression introduced in https://github.com/rust-lang/rust/pull/117500
rustc_target contains some very low-level details that are
specific to different compilation targets and so forth.
For more information about how rustc works, see the rustc dev guide.