move some attribute related structs out ot rustc_attr_ir

[mejrs]

This changes it so that

• rustc_session no longer depends on rustc_attr_ir
• rustc_attr_ir no longer depends on rustc_target (which is a fairly sizeable crate)
• rustc_attr_ir and rustc_target can compile in parallel

Previous graph:

Graph with this PR:

r? @JonathanBrouwer

[rustbot]

Some changes occurred in compiler/rustc_passes/src/check_attr.rs

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred in compiler/rustc_attr_ir

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

clippy is developed in its own repository. If possible, consider making this change to rust-lang/rust-clippy instead.

cc @rust-lang/clippy

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

rustc_codegen_cranelift is developed in its own repository. If possible, consider making this change to rust-lang/rustc_codegen_cranelift instead.

cc @bjorn3

rustc_error_messages was changed

cc @TaKO8Ki

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

[rustbot]

miri is developed in its own repository. If the Miri part of this change can be broken out, consider making this change to rust-lang/miri instead. However, if Miri needs adjusting for rustc changes, just ignore this message.

cc @rust-lang/miri

[rust-log-analyzer]

The job pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   |

For more information about this error, try `rustc --explain E0432`.
[RUSTC-TIMING] priroda test:false 0.279
error: could not compile `priroda` (bin "priroda") due to 1 previous error
warning: build failed, waiting for other jobs to finish...
[RUSTC-TIMING] priroda test:true 0.284
error: could not compile `priroda` (bin "priroda" test) due to 1 previous error
Bootstrap failed while executing `check`
Currently active steps:
check::Priroda { compiler: CompilerForCheck { build_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, rustc_rmeta_sysroot: Some(RmetaSysroot { host_dir: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-rustc-rmeta-artifacts/host", target_dir: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-rustc-rmeta-artifacts/x86_64-unknown-linux-gnu" }), std_rmeta_sysroot: None }, target: x86_64-unknown-linux-gnu } at src/bootstrap/src/core/build_steps/check.rs:854
Build completed unsuccessfully in 0:03:21
  local time: Mon Aug 17 20:07:14 UTC 2026