test(tests/lean/run): add more rewrite tactic tests

tests/lean/run/rewriter13.lean

@@ -0,0 +1,7 @@
+open nat
+
+example (x y : nat) (H1 : sigma.pr1 ⟨x, y⟩ = 0) : x = 0 :=
+begin
+  rewrite ▸* at H1,
+  rewrite H1
+end

tests/lean/run/rewriter14.lean

@@ -0,0 +1,12 @@
+import data.nat
+open nat
+
+definition f [unfold-c 2] (x y z : nat) : nat :=
+x + y + z
+
+attribute of_num [unfold-c 1]
+
+example (x y : nat) (H1 : f x 0 0 = 0) : x = 0 :=
+begin
+  rewrite [▸* at H1, 4>add_zero at H1, H1]
+end