Fundamentally, querying the OS for error codes is a process
that is deeply subject to the whims of chance and fortune.
We can account for OS, but not for every combination of platform APIs.
A compiled binary may not recognize new errors introduced years later.
We should clarify a few especially odd situations, and what they mean:
We can effectively promise nothing.

This allows removing mention of ErrorKind::Uncategorized.
That error variant is hidden quite deliberately, so we
should not explicitly mention it.

If a lint example has an `ignore` tag, but the lint author also includes
the {{produces}} marker, then the output will just contain the text
`{{produces}}`. This adds a check for this mistake and provides help on
how the lint docs should be written.

Some examples may contain multiple lines which trigger the lint.
Previously it would only display the first message.
This updates it so that all matching instances of the lint are displayed.

…calize`

… time-passes`

…idden-documentation, r=ChrisDenton

Clarify `Error::last_os_error` can be weird

Fundamentally, querying the OS for error codes is a process that is deeply subject to the whims of chance and fortune. We can account for OS, but not for every combination of platform APIs. A compiled binary may not recognize new errors introduced years later. We should clarify a few especially odd situations, and what they mean: We can effectively promise nothing... if you ask for Rust to decode errors where none have occurred.

This allows removing mention of ErrorKind::Uncategorized.
That error variant is hidden deliberately, so we should not explicitly mention it.

This fixes rust-lang#106937.

Since you had an opinion also: Does this solution seem acceptable?
r? ``@ChrisDenton``

Add `-Z time-passes-format` to allow specifying a JSON output for `-Z time-passes`

This adds back the `-Z time` option as that is useful for [my rustc benchmark tool](https://github.com/Zoxc/rcb), reverting rust-lang#102725. It now uses nanoseconds and bytes as the units so it is renamed to `time-precise`.

Lint ambiguous glob re-exports

Attempts to fix rust-lang#107563.

We currently already emit errors for ambiguous re-exports when two names are re-exported *specifically*, i.e. not from glob exports. This PR attempts to emit deny-by-default lints for ambiguous glob re-exports.

Remove issue number for `link_cfg`

Fixes rust-lang#72059

Per rust-lang#37406 and its [unstable book entry](https://doc.rust-lang.org/beta/unstable-book/language-features/link-cfg.html), this is an internal feature, and therefore perma-unstable and not being tracked

Fix the ffi_unwind_calls lint documentation

This fixes the [`ffi_unwind_calls`](https://doc.rust-lang.org/nightly/rustc/lints/listing/allowed-by-default.html#ffi-unwind-calls) documentation to show its output correctly. Currently it is showing the text `{{produces}}` which is not how it should look.

This fixes it by not ignoring the example. I'm not sure why it was ignored, as the way the lint currently works it doesn't seem to require external linkage. This also fixes several mistakes in the example:

* There is no `ffi_unwind_calls` feature.
* Denies the lint (which is otherwise allow be default).
* Removes the `mod impl` which is not valid Rust syntax, and doesn't appear to be needed anyways.

The output now looks like:

```
warning: call to foreign function with FFI-unwind ABI
  --> lint_example.rs:10:14
   |
10 |     unsafe { foo(); }
   |              ^^^^^ call to foreign function with FFI-unwind ABI
   |
note: the lint level is defined here
  --> lint_example.rs:2:9
   |
2  | #![warn(ffi_unwind_calls)]
   |         ^^^^^^^^^^^^^^^^

warning: call to function pointer with FFI-unwind ABI
  --> lint_example.rs:12:14
   |
12 |     unsafe { ptr(); }
   |              ^^^^^ call to function pointer with FFI-unwind ABI

```

This also includes some updates to the lint-docs tool to help with this issue:

* Adds a check if a lint documentation has `{{produces}}` with an ignored example, and generates an error.
* All instances of a lint are now displayed. Previously it only showed the first time the lint fires. Some examples may trigger a lint multiple times, and they are all now displayed.

Add `try_canonicalize` to `rustc_fs_util` and use it over `fs::canonicalize`

This adds `try_canonicalize` which tries to call `fs::canonicalize`, but falls back to `std::path::absolute` if it fails. Existing `canonicalize` calls are replaced with it. `fs::canonicalize` is not guaranteed to work on Windows.

Add parentheses properly for method calls

Fixes rust-lang#109436

…rt-check, r=petrochenkov

Move useless_anynous_reexport lint into unused_imports

As mentioned in rust-lang#109003, this check should have been merged with `unused_imports` in the start.

r? `@petrochenkov`