[1/N] Implement Arithmetic lint

[c410-f3r]

Assuming that #8903 is OK, this PR starts the creation of the Arithmetic lint with configurable types.

My current struggle to get a rustc review inspired me to create smaller PRs in order to easy review and make merges as fast as possible. So the first step here only moves the arithmetic.rs file to numeric_arithmetic.rs to make room for the new lint.

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changelog: none

[rust-highfive]

r? @camsteffen

(rust-highfive has picked a reviewer for you, use r? to override)

[Jarcho]

There's no need to split PR's up this much. There isn't much of a reason to accept the change as it stands. As part of a PR adding a lint for any use of an arithmetic operator the change is perfectly fine. Feel free to keep adding to this PR rather than closing it.

Side note the changes you have here will be broken by #8921 when it gets merged.

[c410-f3r]

There's no need to split PR's up this much. There isn't much of a reason to accept the change as it stands. As part of a PR adding a lint for any use of an arithmetic operator the change is perfectly fine. Feel free to keep adding to this PR rather than closing it.

Side note the changes you have here will be broken by #8921 when it gets merged.

There are PRs sitting idle for months and if the Clippy team couldn't merge 9 diff lines in 5 days, my perception is that a full PR would take much, much, much, much longer.

Perhaps another reviewer?

r? rust-lang/rust-clippy (Blah, doesn't work)

[c410-f3r]

r? @llogiq

[llogiq]

Ok. Feel free to make the next PR bigger and directly ask for my review.

@bors r+

[bors]

📌 Commit 4fc0ee6 has been approved by llogiq

[bors]

⌛ Testing commit 4fc0ee6 with merge 9428e2e...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: llogiq
Pushing 9428e2e to master...

[c410-f3r]

Thank you @llogiq