remove obsolete comment

Referenced was removed in 9f492fef

remove AllocId generalization of Pointer

This was only needed for the "snapshot" machinery, which is gone.

r? @oli-obk

bootstrap: also apply unused-attributes hack without deny_warnings

This is a follow-up to https://github.com/rust-lang/rust/pull/70881 that also silences these warnings when deny_warnings is off. They otherwise spam my screen during development and make it hard to see actual warnings.

Cc  @EddyB r? @Mark-Simulacrum

Miri: port error backtraces to std::backtrace

No need to pull in an external dependency if libstd already includes this feature (using the same dependency internally, but... still).

r? @oli-obk

Rename `bitcode-in-rlib` option to `embed-bitcode`

This commit finishes work first pioneered in #70458 and started in #71528.
The `-C bitcode-in-rlib` option, which has not yet reached stable, is
renamed to `-C embed-bitcode` since that more accurately reflects what
it does now anyway. Various tests and such are updated along the way as
well.

This'll also need to be backported to the beta channel to ensure we
don't accidentally stabilize `-Cbitcode-in-rlib` as well.

Rollup of 5 pull requests

Successful merges:

 - #71018 (handle ConstValue::ByRef in relate)
 - #71758 (Remove leftover chalk types)
 - #71760 (Document unsafety for `*const T` and `*mut T`)
 - #71761 (doc: reference does not exist, probably a typo)
 - #71762 (doc: this resulted in a link pointing to a non-existent target)

Failed merges:

 - #71726 (Suggest deref when coercing `ty::Ref` to `ty::RawPtr` with arbitrary mutability)

r? @ghost

doc: this resulted in a link pointing to a non-existent target

doc: reference does not exist, probably a typo

Document unsafety for `*const T` and `*mut T`

Helps with #66219
r? @Mark-Simulacrum

Remove leftover chalk types

Split out from #69406

Since the other PR is having memory problems with `parallel-compiler = true`, figured I should split this out. Surprisingly, this actually changes some errors, and I'm not quite sure why.

r? @nikomatsakis

handle ConstValue::ByRef in relate

fixes #68615

r? @EddyB

Avoid duplicating code for each query

There are at the moment roughly 170 queries in librustc.
The way `ty::query` is structured, a lot of code is duplicated for each query.
I suspect this to be responsible for a part of librustc'c compile time.

The first part of this PR reduces the amount of code generic on the query,
replacing it by code generic on the key-value types. I can split it out if needed.

In a second part, the non-inlined methods in the `QueryAccessors` and `QueryDescription` traits
are made into a virtual dispatch table. This allows to reduce even more the number of generated
functions.

This allows to save 1.5s on check build, and 10% on the size of the librustc.rlib.
(Attributed roughly half and half).
My computer is not good enough to measure properly compiling time.
I have no idea of the effect on performance. A perf run may be required.

cc #65031

Rollup of 5 pull requests

Successful merges:

 - #71744 (remove obsolete comment)
 - #71747 (Remove deadcode in eval_mir_constant_to_operand)
 - #71749 (fix Miri error message padding)
 - #71752 (make Stability doc a more readable (and fix rustdoc warning))
 - #71755 (fix doc reference)

Failed merges:

r? @ghost

fix doc reference

Should of been in e0ce9f8c,
but that had a typo.

make Stability doc a more readable (and fix rustdoc warning)

fix Miri error message padding

I screwed up in the previous PR, and accidentally padded with spaces instead of 0s...

r? @oli-obk

Remove deadcode in eval_mir_constant_to_operand

r? @oli-obk @RalfJung

remove obsolete comment

Referenced was removed in 8770d0f3

This commit finishes work first pioneered in #70458 and started in #71528.
The `-C bitcode-in-rlib` option, which has not yet reached stable, is
renamed to `-C embed-bitcode` since that more accurately reflects what
it does now anyway. Various tests and such are updated along the way as
well.

This'll also need to be backported to the beta channel to ensure we
don't accidentally stabilize `-Cbitcode-in-rlib` as well.

Should of been in e0ce9f8c,
but that had a typo.

submodules: update cargo from 90931d9b3 to 258c89644

Changes:
````
Remove unnecessary loop in `maybe_spurious`
Fix error with git repo discovery and symlinks.
Allow failure when setting file mtime.
Support multiple `--target` flags on the CLI
build-std: Don't treat std like a "local" package.
Allow `cargo package --list` even for things that don't package.
````

I'd like to get https://github.com/rust-lang/cargo/pull/8186 into nightly asap. :)

r? @ehuss

Referenced was removed in 8770d0f3

Changes:
````
Remove unnecessary loop in `maybe_spurious`
Fix error with git repo discovery and symlinks.
Allow failure when setting file mtime.
Support multiple `--target` flags on the CLI
build-std: Don't treat std like a "local" package.
Allow `cargo package --list` even for things that don't package.
````