3011154573
This reverts commit b376f5621b, which is
the main part of #90499, because it turns out that this causes a good
amount of breakage in crates relying on the old behavior.
Fixes #91372.
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.