Update src/stabilization_guide.md

Co-Authored-By: rajcspsg <raj.cs.psg@gmail.com>

Author: mark-i-m

src/stabilization_guide.md

@@ -121,7 +121,7 @@ writing, the next stable release (i.e. what is currently beta) was
 
 Next search for the feature string (in this case, `pub_restricted`)
 in the codebase to find where it appears. Change uses of
-`#![feature(XXX)]` from the stdlib and rustc crates to be
+`#![feature(XXX)]` from the `libstd` and any rustc crates to be
 `#![cfg_attr(stage0, feature(XXX))]`. This includes the feature-gate
 only for stage0, which is built using the current beta (this is
 needed because the feature is still unstable in the current beta).