Add debugging tactics from separate branch

coq/Infra/Ltacs.v

@@ -239,3 +239,13 @@ Ltac destruct_ex H pat :=
   end.
 
 Tactic Notation "destruct_smart" simple_intropattern(pat) hyp(H) := destruct_ex H pat.
+
+(* Debugging tactics, if scripts fail *)
+Ltac debug_term t :=
+  let name := fresh "debug" in
+  let res := (eval compute in t) in
+  assert (t = res) as name by (vm_compute; auto);
+  rewrite name; clear name.
+
+Ltac step f :=
+  cbn iota beta delta [f].