docs: add Rust logo to more compiler crates

c6e6ecb1af 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.

compiler/rustc_codegen_llvm/src/lib.rs

@@ -4,6 +4,9 @@
 //!
 //! This API is completely unstable and subject to change.
 
+#![cfg_attr(not(bootstrap), allow(internal_features))]
+#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![cfg_attr(not(bootstrap), doc(rust_logo))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(extern_types)]
 #![feature(hash_raw_entry)]