Lint casts to u128 in cast_lossless

[Alexendoo]

Reverts #12496 per https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Should.20.60as.20u128.60.20trigger.20cast_lossless

Also changes the lint messages and refactors the suggestion production - Fixes #12695

changelog: [cast_lossless]: lint casts to u128

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[xFrednet]

I think the linked zulip thread is wrong ^^

@Alexendoo could you link the correct one?

[y21]

Looks like there's a missing ) here

[y21]

Also, can this just use Sugg::hir().maybe_par() or does that not work here? I believe the current version won't handle parenthesized expressions like (1i8 + 1i8) as _ correctly. Would need < PREC_POSTFIX or something like that I think?

[Alexendoo]

🙃 I wonder why I did not add tests for this

It was meant to be from_snippet rather than from so that PREC_PREFIX would cover the unary op cases, but that still missed x as u16 as _

I didn't use it initially because Sugg had an issue with macro spans but fixing it was easier than I thought so it does now

[y21]

Also suggesting .into() for as _ is a nice idea, much better than the <_>::from() I had in mind

[y21]

Nice, looks all good to me now, thanks!

@bors r+

[bors]

📌 Commit 6d28e1a has been approved by y21

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6d28e1a with merge 5e6540f...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: y21
Pushing 5e6540f to master...