test(tests/lean/run): add section test

tests/lean/run/section2.lean

@@ -0,0 +1,17 @@
+import data.nat
+
+section foo
+  parameter A : Type
+  definition id (a : A) := a
+  variable a : nat
+  check _root_.id nat a
+end foo
+
+namespace n1
+section foo
+  parameter A : Type
+  definition id (a : A) := a
+  variable a : nat
+  check n1.id _ a
+end foo
+end n1