Fixes #80303.

Rephrase and hopefully clarify the discussion of covariance in `NonNull<T>` documentation.

This is no longer necessary now that rustdoc doesn't run
everybody_loops.

Co-authored-by: Joshua Nelson <[email protected]>
Co-authored-by: Camelid <[email protected]>

This happened because `alloc_query_strings` was never called.

- Show `create_renderer` and `renderer_after_crate` by default
- Don't rewrite `extra_verbose_generic_activity`

This avoids each tool having to separately find and call
`self_profile_alloc_strings`.

- Don't compute the global context if it hasn't yet been computed

  This avoids giving extraneous errors about unresolved names if an error
  occurs during parsing.

More clear documentation for NonNull<T>

Rephrase and hopefully clarify the discussion of covariance in `NonNull<T>` documentation.

I'm very much not an expert so someone should definitely double check the correctness of what I'm saying. At the same time, the new language makes more sense to me, so hopefully it also is more logical to others whose knowledge of covariance basically begins and ends with the [Rustonomicon chapter](https://doc.rust-lang.org/nomicon/subtyping.html).

Related to #48929.

PlaceRef::ty: use method call syntax

Edit rustc_middle::dep_graph module documentation

This is similar to work approved and then closed in #80325 due to a bad rebase.

Avoid hash_slice in VecDeque's Hash implementation

Fixes #80303.

mir: Improve size_of handling when arg is unsized

As discussed on Zulip with `@RalfJung.`

Update cargo

5 commits in a73e5b7d567c3036b296fc6b33ed52c5edcd882e..783bc43c660bf39c1e562c8c429b32078ad3099b
2021-01-12 23:45:39 +0000 to 2021-01-20 19:02:26 +0000
- Fix some issues with `cargo doc` and the new feature resolver. (rust-lang/cargo#9077)
- Implement support for rust-version field in project metadata (rust-lang/cargo#8037)
- Fix a bug in Cargo's cyclic dep graph detection (rust-lang/cargo#9075)
- Typo correction: artifcats -> artifacts (rust-lang/cargo#9081)
- Remove stray backtick from doc (rust-lang/cargo#9079)

Lower closure prototype after its body.

Fixes #79537.

r? `@Mark-Simulacrum`

Add more self-profile info to rustc_resolve

The idea is to help me find out where the time is being spent in compiling the docs for `windows-rs`: microsoft/windows-rs#420 (comment)

Fix <unknown> queries and add more timing info to render_html

Closes #81251.

##  Fix `<unknown>` queries

This happened because `alloc_query_strings` was never called.

##  Add more timing info to render_html

This still has some issues I'm not sure how to work out:

- `create_renderer` and `renderer_after_krate` aren't shown by default.
  I want something like `verbose_generic_activity_with_arg`, but it doesn't exist.

I'm also not sure how to show activities that aren't on by default - I
tried `-Z self-profile -Z self-profile-args=all`, but it didn't show up.

r? `@wesleywiser`

Inline methods of Path and OsString

These methods are not generic, and therefore aren't candidates for cross-crate inlining without an `#[inline]` attribute.

Note library tracking issue template in tracking issue template.

rustdoc: Fix visibility of trait and impl items

Fixes #81274.

r? `@jyn514`

replace RefCell with Cell in FnCtxt

small cleanup

Fix small typo

Fractional part of `12.34e56` seems to be incorrectly stated as '45' and not '34'