add rename-by-pattern tactic

CHANGELOG.md

@@ -43,6 +43,8 @@ Coq 8.8 and 8.9 are no longer supported.
 - Rename `seq_S_end_app` to `seq_S`. (The lemma `seq_S` is also in Coq's stdlib
   since Coq 8.12.)
 - Remove `omega` import and hint database in `tactics` file.
+- Add `rename select <pat> into <name>` tactic to find a hypothesis by pattern
+  and give it a fixed name.
 
 The following `sed` script should perform most of the renaming
 (on macOS, replace `sed` by `gsed`, installed via e.g. `brew install gnu-sed`):

tests/tactics.v

@@ -48,3 +48,6 @@ Proof.
   intros * HH. split_and!; [ destruct_and? HH; assumption | destruct_and?; assumption | ].
   destruct_and?. Fail destruct_and!. assumption.
 Qed.
+
+Goal forall (n : nat), ∃ m : nat, True.
+Proof. intros ?. rename select nat into m. exists m. done. Qed.

theories/tactics.v

@@ -537,6 +537,9 @@ Tactic Notation "select" open_constr(pat) tactic3(tac) :=
 (** [select_revert] reverts the first hypothesis matching [pat]. *)
 Tactic Notation "revert" "select" open_constr(pat) := select pat (fun H => revert H).
 
+Tactic Notation "rename" "select" open_constr(pat) "into" ident(name) :=
+  select pat (fun H => rename H into name).
+
 (** Coq's [firstorder] tactic fails or loops on rather small goals already. In
 particular, on those generated by the tactic [unfold_elem_ofs] which is used
 to solve propositions on sets. The [naive_solver] tactic implements an