Conditional param type should provide the same analysis as condition in code

# Feature request

demo: https://phpstan.org/r/db87d84e-9483-4a85-9506-39e25605ee7a

I would expect
```
@param ($name is array ? null : int) $value
```
to be strictly equal to
```
@param int $value
```
\+
```
if (is_array($name)) {
    $value = null;
}
```