This deprecates:
ReflectionParameter::isArray()
ReflectionParameter::isCallable()
ReflectionParameter::getClass()
These APIs have been superseded by ReflectionParameter::getType()
since PHP 7.0. Types introduced since that time are not available
through the old APIs, and their behavior is getting increasingly
confusing. This is how they interact with PHP 8 union types:
* isArray() will return true if the type is array or ?array,
but not any other union type
* Same for isCallable().
* getClass() will return a class for T|int etc, as long as the
union only contains a single type. T1|T2 will return null.
This behavior is not particularly reasonable or useful, and will
get more confusing as new type system extensions are added.
Closes GH-5209.
