Curtesy of petrochenkov

tcx.crate_name is the appropriate way to retrieve the crate name.

This drops the parking_lot dependency; the ReentrantMutex type appeared
to be unused (at least, no compilation failures occurred).

This is technically a possible change in behavior of its users, as
lock() would wait on other threads releasing their guards, but since we
didn't actually remove any threading or such in this code, it appears
that we never used that behavior (the behavior change is only noticeable
if the type previously was used in two threads, in a single thread
ReentrantMutex is useless).

This is already a query so we're just needlessly copying the data
around.

These impls prevent ergonomic use of the config (e.g., forcing us to use
RefCell) despite all usecases for these structs only using their Display
impls once.

Utilize `?` instead of and_then/map operators

ty::Instance is small and Copy, we should not be adding additional
indirection.

Add #[repr(transparent)] for several types

In some functions, types mentioned in this PR are transmuted into their inner value.
Example for `PathBuf`: https://github.com/rust-lang/rust/blob/master/src/libstd/path.rs#L1132.
This PR adds `#[repr(transparent)]` to those types, so their correct behavior doesn't depend on compiler details. (As far as I understand, currently that line, converting `PathBuf` to `Vec<u8>`, is UB).

Lint on some incorrect uses of mem::zeroed / mem::uninitialized

Cc rust-lang#62825 and https://internals.rust-lang.org/t/make-mem-uninitialized-and-mem-zeroed-panic-for-some-types-where-0-is-a-niche/10605

This does not yet handle `NonNull`/`NonZero*`, but it is a start.

I also improved some doc issues I hit on the way, and added a useful helper to `TyS`.

EDIT: I added the relnotes label mostly as a proposal -- I think this is worth mentioning, but leave the decision up to the release team.

Miri shouldn't look at types

r? @oli-obk

Fixes rust-lang#62137

rename RUST_CTFE_BACKTRACE to RUSTC_CTFE_BACKTRACE

This matches `RUSTC_LOG`. Both affect only rustc, not any Rust program.

Derive Debug for CrateInfo

…k-Simulacrum

Add an example to show how to insert item to a sorted vec

Closes rust-lang#61684
cc rust-lang#61742
r? @Mark-Simulacrum, @jonas-schievink

…GuillaumeGomez

rustdoc: general cleanup

Almost all commits stand alone; but all commits can be reviewed individually.

…ddyb

Copy ty::Instance instead of passing by reference

ty::Instance is small and Copy, we should not be adding additional
indirection.

Fixes rust-lang#63409.

r? @eddyb