Apply suggestions from code review

Co-authored-by: beef <[email protected]>

Author: compiler-errors

Diff for: compiler/rustc_trait_selection/src/traits/specialize/mod.rs

@@ -269,11 +269,11 @@ pub(super) fn specializes(
         return false;
     }
 
-    // create a parameter environment corresponding to an identity instantiation of impl1,
-    // i.e. the most generic instantiation of impl1.
+    // create a parameter environment corresponding to an identity instantiation of the specializing impl,
+    // i.e. the most generic instantiation of the specializing impl.
     let param_env = tcx.param_env(specializing_impl_def_id);
 
-    // Create an infcx, taking the predicates of impl1 as assumptions:
+    // Create an infcx, taking the predicates of the specializing impl as assumptions:
     let infcx = tcx.infer_ctxt().build(TypingMode::non_body_analysis());
 
     let specializing_impl_trait_ref =
@@ -284,7 +284,7 @@ pub(super) fn specializes(
         param_env, specializing_impl_trait_ref, parent_impl_def_id
     );
 
-    // Attempt to prove that impl2 applies, given all of the above.
+    // Attempt to prove that the parent impl applies, given all of the above.
 
     let ocx = ObligationCtxt::new(&infcx);
     let specializing_impl_trait_ref = ocx.normalize(cause, param_env, specializing_impl_trait_ref);