[1.x] Fixes namespace resolution on named arguments

[nunomaduro]

This pull request fixes namespace resolution on named arguments. Here is an example of the before / after:

return my_function(
-   a1: new User,
+   a1: new \App\Models\User,
-   a2: User::create(),
+   a2: \App\Models\User::create(),
-   a3: User::ADMIN_TYPE
+   a3: \App\Models\User::ADMIN_TYPE
);