Add test for issue ocaml#1226 (ocaml#1227)

Author: voodoos

tests/test-dirs/type-enclosing/issue1226.t

@@ -0,0 +1,39 @@
+FIXME
+
+  $ $MERLIN single type-enclosing  -position 5:9 -filename test.ml <<EOF
+  > module Foo = struct
+  >   let bar = 42
+  > end
+  > type t = Foo of int
+  > let a = Foo 3
+  > EOF
+  {
+    "class": "return",
+    "value": [
+      {
+        "start": {
+          "line": 5,
+          "col": 8
+        },
+        "end": {
+          "line": 5,
+          "col": 11
+        },
+        "type": "sig val bar : int end",
+        "tail": "no"
+      },
+      {
+        "start": {
+          "line": 5,
+          "col": 8
+        },
+        "end": {
+          "line": 5,
+          "col": 13
+        },
+        "type": "t",
+        "tail": "no"
+      }
+    ],
+    "notifications": []
+  }