Rollup merge of #138084 - nnethercote:workspace-lints, r=jieyouxu

Use workspace lints for crates in `compiler/`

This is nicer and hopefully less error prone than specifying lints via bootstrap.

r? ``@jieyouxu``

compiler/rustc_codegen_llvm/Cargo.toml

@@ -43,3 +43,6 @@ serde_json = "1"
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 tracing = "0.1"
 # tidy-alphabetical-end
+
+[lints]
+workspace = true

compiler/rustc_codegen_llvm/src/lib.rs

@@ -19,7 +19,6 @@
 #![feature(rustdoc_internals)]
 #![feature(slice_as_array)]
 #![feature(try_blocks)]
-#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::any::Any;