coverage: Change query codegened_and_inlined_items to a plain function

This query has a name that sounds general-purpose, but in fact it has
coverage-specific semantics, and (fortunately) is only used by coverage code.

Because it is only ever called once (from one designated CGU), it doesn't need
to be a query, and we can change it to a regular function instead.

compiler/rustc_middle/src/query/mod.rs

@@ -1882,12 +1882,6 @@ rustc_queries! {
         desc { |tcx| "determining whether `{}` needs codegen", tcx.def_path_str(def_id) }
     }
 
-    /// All items participating in code generation together with items inlined into them.
-    query codegened_and_inlined_items(_: ()) -> &'tcx DefIdSet {
-        eval_always
-        desc { "collecting codegened and inlined items" }
-    }
-
     query codegen_unit(sym: Symbol) -> &'tcx CodegenUnit<'tcx> {
         desc { "getting codegen unit `{sym}`" }
     }