The logging in compiletest was migrated from log crate to a tracing, but
the initialization code was never changed, so logging is non-functional.

Initialize tracing subscriber using default settings.

Fixes rust-lang#78192

Fixes rust-lang#42474.

…stions

…ot ICE

Fix rust-lang#77218. Fix rust-lang#77238.

…fe-fn, r=Mark-Simulacrum

`#[deny(unsafe_op_in_unsafe_fn)]` in sys/wasm

This is part of rust-lang#73904.

This encloses unsafe operations in unsafe fn in `libstd/sys/wasm`.

@rustbot modify labels: F-unsafe-block-in-unsafe-fn

…crum

Tweak `if let` suggestion to be more liberal with suggestion and to not ICE

Fix rust-lang#77218. Fix rust-lang#77238.

…ulacrum

transmute_copy: explain that alignment is handled correctly

The doc comment currently is somewhat misleading because if it actually transmuted `&T` to `&U`, a higher-aligned `U` would be problematic.

…mulacrum

BTreeMap: ban BoxedNode from Root

`NodeRef<marker::Owned, …>` already exists as a representation of root nodes, and it makes more sense to alias `Root` to that than to reuse the space-efficient `BoxedNode` that is oblivious to height, where height is required.

r? @Mark-Simulacrum

…-Simulacrum

Initialize tracing subscriber in compiletest tool

The logging in compiletest was migrated from log crate to a tracing, but
the initialization code was never changed, so logging is non-functional.

Initialize tracing subscriber using default settings.

…Mark-Simulacrum

Add issue template link to IRLO

Tweak match arm semicolon removal suggestion to account for futures

* Tweak and extend "use `.await`" suggestions
* Suggest removal of semicolon on prior match arm
* Account for `impl Future` when suggesting semicolon removal
* Silence some errors when encountering `await foo()?` as can't be certain what the intent was

*Thanks to https://twitter.com/a_hoverbear/status/1318960787105353728 for pointing this out!*

…, r=m-ou-se

Capture output from threads spawned in tests

This is revival of rust-lang#75172.

Original text:
> Fixes rust-lang#42474.
>
> r? `@dtolnay` since you expressed interest in this, but feel free to redirect if you aren't the right person anymore.

---

Closes rust-lang#75172.

Fix rust-lang#78192

Check which places are marked dead.

Fixes rust-lang#78192

Do not try to report on closures to avoid ICE

Fixes rust-lang#78262