CLJS-2841: [spec] instrument exception doesn't contain function name in ex-data

Author: mfikes

src/main/cljs/cljs/spec/test/alpha.cljs

@@ -96,6 +96,7 @@
                                         (.-stack (js/Error.))
                                         (get-env) nil))
                              ed (merge (assoc (s/explain-data* spec [role] [] [] data)
+                                         ::s/fn (->sym v)
                                          ::s/args args
                                          ::s/failure :instrument)
                                   (when caller