Enforce in bootstrap that clippy must have stage at least 1

[Kobzol]

This mostly piggybacks on the previous x check rework.

The new "rules" follow the new staging logic. So x clippy <foo> lints foo using stage0 Clippy. x clippy --stage 2 <foo> lints foo using stage1 Clippy (which is built from in-tree sources).

I had to fix some latent issues with prepare_compiler_for_check along the way.

Checking rustc_private tools should now check less compiler crates (or rather not check compiler examples/tests/etc.), potentially speeding it up slightly.

I also had to switch x clippy ci to stage 2, so that it actually lints stuff using in-tree Clippy.

r? @jieyouxu

[rustbot]

This PR modifies src/bootstrap/src/core/config.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

[rust-log-analyzer]

The job aarch64-gnu-llvm-19-2 failed! Check out the build log: (web) (plain enhanced) (plain)

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

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Snapshot Summary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Snapshot: check_compiler_no_explicit_stage
Source: src/bootstrap/src/core/builder/tests.rs:1278
────────────────────────────────────────────────────────────────────────────────
Expression: ctx.config("check").path("compiler").render_steps()
────────────────────────────────────────────────────────────────────────────────
-old snapshot
+new results
────────────┬───────────────────────────────────────────────────────────────────
    0     0 │ [check] rustc 0 <host> -> rustc 1 <host>
          1 │+[check] rustc 0 <host> -> rustc 1 <host>
    1     2 │ [check] rustc 0 <host> -> rustc_codegen_cranelift 1 <host>
    2     3 │ [check] rustc 0 <host> -> rustc_codegen_gcc 1 <host>
────────────┴───────────────────────────────────────────────────────────────────
Stopped on the first failure. Run `cargo insta test` to run all snapshots.

thread 'core::builder::tests::snapshot::check_compiler_no_explicit_stage' panicked at /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/insta-1.43.1/src/runtime.rs:679:13:
snapshot assertion for 'check_compiler_no_explicit_stage' failed in line 1278
---
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Snapshot Summary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Snapshot: check_compiler_stage_1
Source: src/bootstrap/src/core/builder/tests.rs:1309
────────────────────────────────────────────────────────────────────────────────
Expression: ctx.config("check").path("compiler").stage(1).render_steps()
────────────────────────────────────────────────────────────────────────────────
-old snapshot
+new results
────────────┬───────────────────────────────────────────────────────────────────
    0     0 │ [check] rustc 0 <host> -> rustc 1 <host>
          1 │+[check] rustc 0 <host> -> rustc 1 <host>
    1     2 │ [check] rustc 0 <host> -> rustc_codegen_cranelift 1 <host>
    2     3 │ [check] rustc 0 <host> -> rustc_codegen_gcc 1 <host>
────────────┴───────────────────────────────────────────────────────────────────
Stopped on the first failure. Run `cargo insta test` to run all snapshots.

thread 'core::builder::tests::snapshot::check_compiler_stage_1' panicked at /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/insta-1.43.1/src/runtime.rs:679:13:
snapshot assertion for 'check_compiler_stage_1' failed in line 1309

---- core::builder::tests::snapshot::check_compiler_stage_2 stdout ----
Running test in /tmp/.tmp0VdCSp
##[group]Building LLVM for aarch64-unknown-linux-gnu
##[endgroup]
---
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Snapshot Summary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Snapshot: check_compiler_stage_2
Source: src/bootstrap/src/core/builder/tests.rs:1323
────────────────────────────────────────────────────────────────────────────────
Expression: ctx.config("check").path("compiler").stage(2).render_steps()
────────────────────────────────────────────────────────────────────────────────
-old snapshot
+new results
────────────┬───────────────────────────────────────────────────────────────────
    0     0 │ [build] llvm <host>
    1     1 │ [build] rustc 0 <host> -> rustc 1 <host>
    2     2 │ [build] rustc 1 <host> -> std 1 <host>
    3     3 │ [check] rustc 1 <host> -> rustc 2 <host>
          4 │+[check] rustc 1 <host> -> rustc 2 <host>
    4     5 │ [check] rustc 1 <host> -> rustc_codegen_cranelift 2 <host>
    5     6 │ [check] rustc 1 <host> -> rustc_codegen_gcc 2 <host>
────────────┴───────────────────────────────────────────────────────────────────
Stopped on the first failure. Run `cargo insta test` to run all snapshots.

thread 'core::builder::tests::snapshot::check_compiler_stage_2' panicked at /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/insta-1.43.1/src/runtime.rs:679:13:
snapshot assertion for 'check_compiler_stage_2' failed in line 1323

---- core::builder::tests::snapshot::check_cross_compile stdout ----
Running test in /tmp/.tmpGBifag
##[group]Building LLVM for aarch64-unknown-linux-gnu
##[endgroup]
---
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Snapshot Summary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Snapshot: check_cross_compile
Source: src/bootstrap/src/core/builder/tests.rs:1340
────────────────────────────────────────────────────────────────────────────────
Expression: ctx.config("check").targets(&[TEST_TRIPLE_1]).hosts(&[TEST_TRIPLE_1]).render_steps()
────────────────────────────────────────────────────────────────────────────────
-old snapshot
+new results
────────────┬───────────────────────────────────────────────────────────────────
    1     1 │ [build] rustc 0 <host> -> rustc 1 <host>
    2     2 │ [build] rustc 1 <host> -> std 1 <host>
    3     3 │ [build] rustc 1 <host> -> std 1 <target1>
    4     4 │ [check] rustc 1 <host> -> rustc 2 <target1>
          5 │+[check] rustc 1 <host> -> rustc 2 <target1>
    5     6 │ [check] rustc 1 <host> -> Rustdoc 2 <target1>
    6     7 │ [check] rustc 1 <host> -> rustc_codegen_cranelift 2 <target1>
    7     8 │ [check] rustc 1 <host> -> rustc_codegen_gcc 2 <target1>
    8     9 │ [check] rustc 1 <host> -> Clippy 2 <target1>
────────────┴───────────────────────────────────────────────────────────────────
Stopped on the first failure. Run `cargo insta test` to run all snapshots.

thread 'core::builder::tests::snapshot::check_cross_compile' panicked at /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/insta-1.43.1/src/runtime.rs:679:13:
snapshot assertion for 'check_cross_compile' failed in line 1340
---
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Snapshot Summary ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Snapshot: check_library_skip_without_download_rustc-2
Source: src/bootstrap/src/core/builder/tests.rs:1440
────────────────────────────────────────────────────────────────────────────────
Expression: ctx.config("check").paths(&["library", "compiler"]).args(&args).render_steps()
────────────────────────────────────────────────────────────────────────────────
-old snapshot
+new results
────────────┬───────────────────────────────────────────────────────────────────
    0     0 │ [check] rustc 0 <host> -> rustc 1 <host>
          1 │+[check] rustc 0 <host> -> rustc 1 <host>
    1     2 │ [check] rustc 0 <host> -> rustc_codegen_cranelift 1 <host>
    2     3 │ [check] rustc 0 <host> -> rustc_codegen_gcc 1 <host>
────────────┴───────────────────────────────────────────────────────────────────
Stopped on the first failure. Run `cargo insta test` to run all snapshots.

thread 'core::builder::tests::snapshot::check_library_skip_without_download_rustc' panicked at /cargo/registry/src/index.crates.io-1949cf8c6b5b557f/insta-1.43.1/src/runtime.rs:679:13:
snapshot assertion for 'check_library_skip_without_download_rustc-2' failed in line 1440


failures:
    core::builder::tests::snapshot::check_compiler_no_explicit_stage
    core::builder::tests::snapshot::check_compiler_stage_1