docs: add Rust logo to more compiler crates

[notriddle]

c6e6ecb added it to some of the compiler's crates, but avoided adding it to all of them to reduce bit-rot. This commit adds to more.

r? @GuillaumeGomez

[rustbot]

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo

rustc_error_messages was changed

cc @davidtwco, @compiler-errors, @JohnTitor, @TaKO8Ki

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

[fmease]

This obviously falls under t-rustdoc{,-contributors}'s purview.

r? fmease @bors r+ rollup

[bors]

📌 Commit 2ff2624 has been approved by fmease

It is now in the queue for this repository.

[bors]

⌛ Testing commit 2ff2624 with merge 631a116...

[bors]

☀️ Test successful - checks-actions
Approved by: fmease
Pushing 631a116 to master...

[rust-timer]

Finished benchmarking commit (631a116): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.5%	[1.0%, 2.1%]	3
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	1.5%	[1.0%, 2.1%]	3

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 625.421s -> 625.939s (0.08%)
Artifact size: 305.57 MiB -> 305.58 MiB (0.00%)

[bjorn3]

Please see

// Note: please avoid adding other feature gates where possible

below. I recently added -Zallow-features=rustc_private to cg_clif's build system to avoid extra features like this, but that change hasn't been synced back to this repo yet. But now that I am trying to sync to cg_clif's repo it causes a build error. I had to add an extra condition on the doc cfg to fix this: rust-lang/rustc_codegen_cranelift@bdc597d.