Add std_instead_of_core, std_instead_of_alloc, alloc_instead_of_core

[i509VCB]

Closes #7724

Introduces 3 new lints:

• std_instead_of_core - lints items resolved through std which are available in core
• std_instead_of_alloc - lints items resolved through std which are available in alloc
• alloc_instead_of_core - lints items resolved through alloc which are available in core

Though the original issue only mentions std_instead_of_alloc, the other two lints could be useful as well.

questions:

• what do I call the file the lints live in? I was thinking std_reexports?

changelog: new lint's: [std_instead_of_core], [std_instead_of_alloc], [alloc_instead_of_core]

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Manishearth (or someone else) soon.

Please see the contribution instructions for more information.

[bors]

☔ The latest upstream changes (presumably #9105) made this pull request unmergeable. Please resolve the merge conflicts.

[Manishearth]

looks good, just needs a rebase!

[i509VCB]

Fixed the merge conflicts

[i509VCB]

Actually sorry do not merge for a moment,

Fixed, good thing git reflog exists otherwise I almost just force pushed away the lint I wrote

[Manishearth]

@bors r+

thanks!

[xFrednet]

Looks like bors was sleeping. I've added a changelog entry for the new lints

@bors r=Manishearth

[bors]

📌 Commit 2f825db has been approved by Manishearth

It is now in the queue for this repository.

[bors]

⌛ Testing commit 2f825db with merge c9f0d1a...

[xFrednet]

@bors ping

[bors]

😪 I'm awake I'm awake

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Manishearth
Pushing c9f0d1a to master...