If testing 'property' is a function, following code will report better errors than "not a property".
```d
struct S {
    void foo(int) {}
    void bar(int, string) {}
}
void main() {
    S s;
    s.foo;
    s.bar = 10;
}
```

Errors:
```
Error: function test.S.foo (int _param_0) is not callable using argument types ()
Error: function test.S.bar (int _param_0, string _param_1) is not callable using argument types (int)
```