Add cram test to reproduce

Author: Lucccyo

tests/test-dirs/signature-help/issue_fun_name.t

@@ -0,0 +1,33 @@
+FIXME: Signature help should not appear on the name of the function (here on `map`):
+  $ cat > test.ml <<'EOF'
+  > let v = List.map Fun.id
+  > EOF
+
+  $ $MERLIN single signature-help -position 1:15 -filename test < test.ml
+  {
+    "class": "return",
+    "value": {
+      "signatures": [
+        {
+          "label": "List.map : ('_weak1 -> '_weak1) -> '_weak1 list -> '_weak1 list",
+          "parameters": [
+            {
+              "label": [
+                11,
+                31
+              ]
+            },
+            {
+              "label": [
+                35,
+                47
+              ]
+            }
+          ]
+        }
+      ],
+      "activeParameter": 0,
+      "activeSignature": 0
+    },
+    "notifications": []
+  }