Kept 1.42 around for Thunderbird.
i686-apple-darwin is no longer supported upstream. We could still
support building it, for this one release, since we have the binary
for the previous release, (or bootstrap it for future releases from
Rust 1.42,) but since this release is the one that drops support, I
think it makes sense to do it now. (And probably nobody is using it
anyway.)
simplify the boostrap hashes a bit
build with bundled llvm:
the rust project has forked the llvm compiler to solve some
issues.
With pkgs.llvm the test suite fails.
See https://github.com/rust-lang/rust/pull/43026
And PR #30088
Also updates beta, nightly, nightlyBin, and bootstrap compilers.
Also updates the registry.
Also consolidates logic between bootstrap and nightlyBin compilers.
Also contains some miscellaneous cleanups.
Also patches firefox to build with the newer cargo
