…t declared in their `Cargo.toml`.

If the rust-enabled lldb was built, then use it when running the
debuginfo tests.  Updating the lldb submodule was necessary as this
needed a way to differentiate the rust-enabled lldb, so I added a line
to the --version output.

This adds compiletest commands to differentiate between the
rust-enabled and non-rust-enabled lldb, as is already done for gdb.  A
new "rust-lldb" header directive is also added, but not used in this
patch; I plan to use it in rust-lang#54004.

This updates all the tests.

I noticed a small typo while reading over this document.

In  rust-lang#51833, I improved the performance of `copy_undef_mask()`. As such, the old FIXME wasn't appropriate anymore. The main remaining thing left to do is to implement a fast path for non-overlapping copies (per @oli-obk).

…ror, r=GuillaumeGomez

Add doc for impl From for Std Error

As part of issue rust-lang#51430 (cc @skade).

I am not sure if it is going to a correct direction so put up here so that people can comment.

Add checking for tool distribution in Tier 1

This fixes rust-lang#54483
r? @kennytm

…idtwco

[NFC] `getopts` is used by `librustc` and `librustc_driver`, but isn't declared in their `Cargo.toml`.

Cleanup rustc/ty part 2

The second part of cleanups and minor improvements for rustc/ty.
- improve allocations
- calculate span after a possible early continue
- simplify some patterns
- mark a comment as FIXME
- whitespace fixes

The PR is independent from from the first part.

Make spec_extend use for_each()

`for_each` will use an iterator's own implementation of `try_fold`, which I understand to be generally preferable (because nested iterator adapter's will use each other's `try_fold` and be designed for the specific adaptation in a way that promotes performance and inlining.

Run debuginfo tests against rust-enabled lldb, when possible

If the rust-enabled lldb was built, then use it when running the
debuginfo tests.  Updating the lldb submodule was necessary as this
needed a way to differentiate the rust-enabled lldb, so I added a line
to the --version output.

This adds compiletest commands to differentiate between the
rust-enabled and non-rust-enabled lldb, as is already done for gdb.  A
new "rust-lldb" header directive is also added, but not used in this
patch; I plan to use it in rust-lang#54004.

This updates all the tests.

Fix typo in CONTRIBUTING.md

I noticed a small typo while reading over this document.

…i-obk

Update a FIXME in memory.rs

In  rust-lang#51833, I improved the performance of `copy_undef_mask()`. As such, the old FIXME wasn't appropriate anymore. The main remaining thing left to do is to implement a fast path for non-overlapping copies (per @oli-obk).

r? @oli-obk

Update clippy

None

A handful of cleanups for rustc/mir

- use the "regular" `into()` instead of `graphviz::IntoCow` in `mod.rs`
- `format!("{}", x)` > `x.to_string()`
- remove one unnecessary `String` allocation
- shorten the logic of one loop
- `assert!(x == y)` > `assert_eq!(x, y)`
- whitespace & formatting fixes

r? @oli-obk