This makes the m68k arch match the other GNU/Linux based targets.

This will make 'lld' available locally now, instead of
needing to wait for the next LLVM submodule bump.

Fix ICE in `check_must_not_suspend_ty()`

Fixes rust-lang#91334. I have also used `TyS::tuple_fields()` (instead of the `SubstsRef` directly) to get the tuple fields, because that's what [the documentation](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/enum.TyKind.html#variant.Tuple) says, although it doesn't seem to make a difference in practice (this is not what fixed the ICE).

…, r=jsha

Simplify --no-headless option for rustdoc-gui tester

It adds a message stating the change for the concurrency and also remove the extra condition when running the tests.

r? `@camelid`

compiler/rustc_target: make m68k-unknown-linux-gnu use the gnu base

This makes the m68k arch match the other GNU/Linux based targets by setting the environment to gnu.

Update doc about code block edition attributes

…imulacrum

Bump download-ci-llvm-stamp for LLD inclusion

This will make 'lld' available locally now, instead of
needing to wait for the next LLVM submodule bump.