Add a new tooltool package for x86_64-unknown-linux-gnu hosts
with the i686-pc-windows-msvc and i686-pc-windows-gnu standard
libraries for the benefit of the cross-mingw builds.
Add the mingw32 releng.manifest to the update list for
new tooltool packages.
MozReview-Commit-ID: KkYPfAojFU
This is needed before we can upgrade to flake8 3.3.0, as that version starts flagging these errors.
These files were modified by running:
autopep8 --select E305 --in-place -r <dir>
on the affected directories. I did it one dir at a time and verified the result after each.
MozReview-Commit-ID: FmlsfiKIbtr
Update rust-build docker image source to v0.4.3. This includes
some recent to how verification and taskcluster work to maintain
working scripts, and some changes for the newer cargo-building-
cargo build system, which aren't sufficient for bootstrapping.
MozReview-Commit-ID: 4IdbKVvco8m
