The Tier 1 i686 and x86_64 windows mingw targets are broken and have been broken for a long time. The core::arch module hasn’t passed any tests on these targets for months or years. The libc crate doesn’t even link on these targets by default: users need to manually overwrite some of the DLLs that we ship with rustup. Etc.
In all this time, nobody has actually even filled an issue about this, much less submit PRs addressing these issues.
There are many tier 2 targets that are better maintained and tested than these.
So I want to propose to demote them to tier 2, and if they start failing to build, continue demoting them to tier 3.
If at some point a group of maintainers for these targets materializes, and they manage to bring them to tier 2 or tier 3 quality again, we should definitely re-evaluate their tier-status. But in the mean time, it doesn’t make sense to require users that have no interest on these targets working to maintain them.