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_const_eval/src/lib.rs

@@ -4,6 +4,9 @@ Rust MIR: a lowered representation of Rust.
 
 */
 
+#![cfg_attr(not(bootstrap), allow(internal_features))]
+#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![cfg_attr(not(bootstrap), doc(rust_logo))]
 #![deny(rustc::untranslatable_diagnostic)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]