iphone_mitigations.md

We list mitigations added in all iPhone versions.

Version (and date)	Mitigation	References
at least up to iPhone X	no ASLR in BootROM/iBoot (this is not a mitigation but worth mentioning)	1 2
at least up to iPhone X	UNSECURE_MEMORY at a static address in BootROM/iBoot (this is not a mitigation but worth mentioning)	2
A9X i.e. >= iPad Pro, iPad 6th generation, iPhone 7	W^X in BootROM/iBoot	3 4
?	ARMv8.3-PAuth	5 6