Refine the lintstore section

[tshepang]

cc #1414

[tshepang]

@JohnTitor I do not understand the date-check sentence, so please bump it if it's still current (and maybe explain it some more).

Here it is:

As of February 2022, we lint against direct declarations without the use of the macro today (although this may change in the future, as the macro is somewhat unwieldy to add new fields to, like all macros).

[JohnTitor]

It'd be better to link to the nightly rustc doc so we can see if it's moved as a link checker failure. Also, it should be on rustc_lint_defs, right?

[tshepang]

Oh kool, didn't think of link checker.
Also, did not notice that rust_lint::Lint is a re-export... thanks.

[JohnTitor]

@JohnTitor I do not understand the date-check sentence, so please bump it if it's still current (and maybe explain it some more).

Here it is:

As of February 2022, we lint against direct declarations without the use of the macro today (although this may change in the future, as the macro is somewhat unwieldy to add new fields to, like all macros).

I think the "we lint~" part and the "although this~" part talk about different things. The first says linting by rustc doesn't work on macros. The second says we use the declare_lint macro, but it may be changed in the future. The original paragraph is here: https://github.com/rust-lang/rustc-dev-guide/pull/476/files#diff-8f8ad089b3a6deea75fb8bc35716ff0b43bb6bfaf16e639afac64ed033a8ef37R16-R20

The date reference is for the first, so I think the situation still continues and we could just update the date but we could also improve the wording, I also think it's kinda confusing.

[tshepang]

that seems to conflict with what is written there, but I pushed the update with the new date regardless

[JohnTitor]

I mean, we should do rewording something like:

First, we have the lint declarations themselves: this is where the name and default lint level and other metadata come from. These are normally defined by way of the [declare_lint!](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_session/macro.declare_lint.html) macro, which boils down to a static with type [&rustc_lint_defs::Lint](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint_defs/struct.Lint.html) (although this may change in the future, as the macro is somewhat unwieldy to add new fields to, like all macros).

As of Aug 2022, we lint against direct declarations without the use of the macro.

[tshepang]

@JohnTitor I pushed

[JohnTitor]

Thanks!

[anirudh24seven]

I think 7b5c503 did not remove the previous paragraph while adding the new paragraph. Raising a PR to remove the near-duplicate paragraph.