Remove unnecessary unsafe from format_args expansion

[davidlattimore]

No description provided.

[davidlattimore]

Relevant history:

• 2021-08-24: Rust changed expansion of the format_args! to use unsafe - Get piece unchecked in write rust#83302
• 2021-08-26: rust-analyzer was changed to accomodate this - Fix missing unsafe block for the nightly change #10032
• 2021-09-23: Rust changed to no longer use unsafe in format_args! - Use ZST for fmt unsafety rust#89139

std::fmt::Arguments::new_v1 was marked unsafe only in 1.56, but was safe in prior and later releases. So this commit will reintroduce issue #10022 for anyone using exactly rust version 1.56. Question is... do you think it has been long enough yet? If anyone were stuck on 1.56, they could work around the issue by adding "missing-unsafe" to the list of disabled diagnostics in rust-analyzer's settings.

[lnicola]

do you think it has been long enough yet?

Lol, we still have users on 1.42 (though proc macros don't work there).

But yeah, if this only applies to a single version, I'm not opposed to it.

[jonas-schievink]

We support current stable only, users that need older Rust versions can use an older rust-analyzer.

@bors r+

[bors]

📌 Commit 6f819e3 has been approved by jonas-schievink

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6f819e3 with merge c419aa9...

[bors]

☀️ Test successful - checks-actions
Approved by: jonas-schievink
Pushing c419aa9 to master...

[str4d]

So this commit will reintroduce issue #10022 for anyone using exactly rust version 1.56.

Aha, this explains why I've been seeing this again for the past few months. 1.56 is a very common MSRV for much of the cryptography ecosystem (for a few reasons, one of which is that it's the earliest Rust version supporting the 2021 edition), so many of the workspaces have overrides set to ensure compatibility. But following the steps in https://rust-analyzer.github.io/manual.html#toolchain were sufficient to remove the errors for me.