[clang] [llvm] [AArch64][PAC] Sign block addresses used in indirectbr. (PR #97647)

[Ahmed Bougacha via cfe-commits]

ahmedbougacha wrote:

> Please make sure you have a testcase for computing the difference between two blockaddresses (void g(int*); int f() { static int x = &&A-&&B; A:g(&x);B:return x; }). Not sure how you should handle that case.

Oh yeah, we can't handle that at all, I don't think!  The best we can do is probably to declare it disallowed and try to diagnose it in the frontend as best we can..  I don't think we ever looked into that, I'll give it a try

https://github.com/llvm/llvm-project/pull/97647