This is a subset of the patches I have on my rust fork to compile rustc
for wasm32-wasip1.

The `regioncx` and `borrow_set` fields can be references instead of
`Rc`. They use the existing `'a` lifetime. This avoids some heap
allocations and is a bit simpler.

Refcounting isn't needed.

It can own these two fields.

Either `&T` or `Rc<T>` is preferable.

By making it own two of its fields.

…r=pnkfelix

Don't allow the `#[pointee]` attribute where it doesn't belong

Error if the `#[pointee]` attribute is applied to anything but generic type parameters.

Closes rust-lang#128485
Related to rust-lang#123430

…tiple-candidates, r=Kobzol

skip in-tree compiler build for llvm-bitcode-linker if ci-rustc is on

Similar to rust-lang#108767, resolves the `multiple candidates` problem for ci-rustc.

See rust-lang#122709 (comment) for more context.

Blocker for rust-lang#122709.

…idtwco

Couple of changes to make it easier to compile rustc for wasm

This is a subset of the patches I have on my rust fork to compile rustc for wasm32-wasip1.

`rustc_borrowck` memory management tweaks

Minor cleanups in `rustc_borrowck` relating to memory management.

r? `@lqd`

Remove valgrind test suite and support from compiletest, bootstrap and opt-dist

The `run-pass-valgrind` test suite is not exercised in CI, and as far as I'm aware nobody runs it (asked in https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/Are.20the.20valgrind.20tests.20even.20used.20by.20anyone.3F). What's remaining of valgrind support in compiletest isn't even properly hooked up with bootstrap.

The existing valgrind logic in compiletest is also straight up questionable, i.e.

https://github.com/rust-lang/rust/blob/1b3b8e7b0265162853c650ead09905bc3cdaeae9/src/tools/compiletest/src/runtest/valgrind.rs#L7-L12

It just runs valgrind tests as `rpass` if no valgrind path is provided to compiletest from bootstrap -- but bootstrap doesn't even pass a valgrind path to compiletest in the first place, so this always ran as `rpass` tests. So what is this even testing?

So if it's not testing anything, let's delete it.

Closes rust-lang#44816 by deleting the test suite :3

<img src="https://github.com/user-attachments/assets/99525bf7-e85b-40ba-9281-e4e1e275c4e8" width=300 />

…nding, r=jieyouxu

Fix used_underscore_binding in rustc_serialize

Hi,

This PR fixes the following clippy warnings in rustc_serialize

```
warning: used underscore-prefixed binding
   --> compiler/rustc_serialize/src/opaque.rs:443:27
    |
443 |         debug_assert_eq!((_end_pos - _start_pos), IntEncodedWithFixedSize::ENCODED_SIZE);
    |                           ^^^^^^^^
    |
note: binding is defined here
   --> compiler/rustc_serialize/src/opaque.rs:442:13
    |
442 |         let _end_pos = e.position();
    |             ^^^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#used_underscore_binding
    = note: requested on the command line with `-W clippy::used-underscore-binding`

warning: used underscore-prefixed binding
   --> compiler/rustc_serialize/src/opaque.rs:443:38
    |
443 |         debug_assert_eq!((_end_pos - _start_pos), IntEncodedWithFixedSize::ENCODED_SIZE);
    |                                      ^^^^^^^^^^
    |
note: binding is defined here
   --> compiler/rustc_serialize/src/opaque.rs:440:13
    |
440 |         let _start_pos = e.position();
    |             ^^^^^^^^^^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#used_underscore_binding
```

Best regards,
Michal

Mark Boxy as on vacation

Boxy asked me to do this since she's busy :D

cc `@BoxyUwU`