Rust: document rustfmt macro preservation

[teor2345]

Some common std macros get reformatted. But by default rustfmt Is conservative and preserves macro formatting.

[TheSven73]

Can contributions from pseudonymous contributors be accepted upstream?
See https://github.com/Rust-for-Linux/linux/blob/rust/Documentation/process/1.Intro.rst, second-to-last paragraph.

[ojeda]

No, they cannot (in general).

[teor2345]

I avoid using my legal name for a bunch of different reasons. It's not really worth changing that to get a 2 line clarification into a document.

However, I'm happy to disclaim all copyright in these changes (as a trivial change) if that helps.

Or I could license them under GPL v2 or BSD, so someone else can sign them off under Developer's Certificate of Origin 1.1, clause (b):

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

Or you could just close this PR 😞

[ojeda]

IIRC there have been some exceptions in the past in rare cases when the individual is personally known by a high-level maintainer but wishes to remain anonymous for some reason.

I have asked if one of the two solutions you propose would be enough -- let's see.

[ojeda]

They told me we need to reject it, sorry.

The solutions above are not enough, even if the statements are public, because we would not know who is behind them.