I know that ARM Pointer Authentication feature is supported on all ARMv8.3-A processors, and this version was presented at 10/2016. RPi 4 Model B was released last year so there is a good chance the version of the SoC processor supports this feature, but in all the specs I found the processor version is just ARMv8-A, without mentioning the sub-section.
I'm a Software Security researcher, and I'm looking specifically for the Pointer Authentication feature so it's important to me to confirm its exists. Thanks in advance.
EDIT: The syntax for using this feature is described in the picture below: