Replace O(n^3) text matching with inexpensive hash set lookups.

On my machine this reduces the total runtime of complete
run-make-fulldeps suite from roughly 75 seconds to 45 seconds.

…nd Arc

Co-Authored-By: Mazdak Farrokhzad <[email protected]>

Removed parameters not used in the macro

Co-Authored-By: Oliver Scherer <[email protected]>

gate rustc_on_unimplemented under rustc_attrs

Move `rustc_on_implemented` from the `on_implemented` gate to `rustc_attrs` as it is internal.

Closes rust-lang#29628

r? @varkor

…=alexcrichton

Optimize long-linker-command-line test

Replace O(n^3) text matching with inexpensive hash set lookups.

On my machine this reduces the total runtime of complete
run-make-fulldeps suite from roughly 75 seconds to 45 seconds.

Improve uninit/zeroed lint

* Also warn when creating a raw pointer with a NULL vtable.
* Also identify `MaybeUninit::uninit().assume_init()` and `MaybeUninit::zeroed().assume_init()` as dangerous.

HIR docs: mention how to resolve method paths

Do not require extra LLVM backends for `x.py test` to pass

For long time our testing passed with a partially built LLVM
```
[llvm]
targets = "X86;ARM"
```
, a [recent PR](rust-lang#65809) changed that.

improve from_raw_parts docs

Triggered by rust-lang/rfcs#2806. Hopefully this helps clarify that joining slices across allocations is not possible in Rust currently.

r? @Centril

…entril

Improve std::thread::Result documentation

Thanks to @dtolnay for pointing out the different premise of the contents of the `Err` variant in `std::thread::Result` WRT normal error handling.

…RalfJung

Fixed PhantomData markers in Arc and Rc

Include owned internal structs in `PhantomData` markers in `Arc` (`PhantomData<T>` => `PhantomData<ArcInner<T>>`) and `Rc` (`PhantomData<T>` => `PhantomData<RcBox<T>>`).

Remove unused parameters in `__thread_local_inner`

Fixes rust-lang#65993.

Miri: Refactor to_scalar_ptr out of existence

`to_scalar_ptr` is somewhat subtle as it just throws away the 2nd component of a `ScalarPair` if there is one -- without any check if this is truly a pointer or so. And indeed we used it wrong on two occasions!

So I fixed those two, and then refactored things such that everyone calls `ref_to_mplace` instead (which they did anyway, I just moved up the calls), which is the only place that should interpret a `ScalarPair` as a wide ptr -- and it checks the type first. Thus we can remove `to_scalar_ptr` and `to_meta`.

r? @oli-obk

Fix broken link in README

The link to the rustc guide on building and running the compiler is broken. It was broken in [rustc-guide#491](rust-lang/rustc-dev-guide#491).

Update link on CONTRIBUTING.md

This is a lost article of rust-lang#66162
Follow-up for rust-lang/rustc-dev-guide#491

CC: @mark-i-m