[v4] Add meta-programming macros for ARM64/AArch64 name change to capstone.h

[Rot127]

Adds the meta programming macros for the ARM64 -> AArch64 name change to the v4 branch.

[kabeor]

Considering we no longer maintain the v4 version, no need to bother with it. I will close this PR, if you have any ideas, feel free to reopen it :)

[Rot127]

Considering that v5 is only a few months old we should merge this nonetheless IMHO.
There might be some who still have v4 running and want to go directly to v6.

[kabeor]

But the people who want to use v6 will install v6 directly, so the capstone.h will be overlay right?

[Rot127]

Not if different versions of Capstone are cloned as sub-module. If a project's code needs to be compatible with v4, v5 and v6 each, they simply can use those macros in their code to wrap it around enum names and the like (e.g. CS_AARCH64(INS_BR)).
Hence those macros need to be present in any version of Capstone they clone.

Or do I miss your point?

[kabeor]

Well, that's a good point. Merged.

[kabeor]

Oh, still, we need tests. @Rot127

[XVilka]

It probably even makes sense to release a small patch version in 4.x series