Merge branch 'tcforall2_forall' into 'master'

Added TCForall2_Forall2 lemma

See merge request iris/stdpp!107

theories/list.v

@@ -3963,6 +3963,9 @@ Instance TCForall_app {A} (P : A → Prop) xs ys :
   TCForall P xs → TCForall P ys → TCForall P (xs ++ ys).
 Proof. rewrite !TCForall_Forall. apply Forall_app_2. Qed.
 
+Lemma TCForall2_Forall2 {A B} (P : A → B → Prop) xs ys : TCForall2 P xs ys ↔ Forall2 P xs ys.
+Proof. split; induction 1; constructor; auto. Qed.
+
 Section positives_flatten_unflatten.
   Local Open Scope positive_scope.