fix function parsing

src/Language/Wasm/Parser.y

@@ -790,8 +790,8 @@ signature_locals_body1 :: { Function }
     | 'param' ident valtype ')' signature_locals_body {
         prependFuncParams [ParamType (Just $2) $3] $5
     }
-    | 'result' list(valtype) ')' signature_locals_body {
-        prependFuncResults $2 $4
+    | 'result' list(valtype) ')' locals_body {
+        prependFuncResults $2 $ emptyFunction { locals = fst $4, body = snd $4 }
     }
     | locals_body1 {
         emptyFunction { locals = fst $1, body = snd $1 }