[llvm-branch-commits] AArch64: Relax restriction on discriminator when PAuth ifunc used. (PR #170945)

[Peter Collingbourne via llvm-branch-commits]

https://github.com/pcc created https://github.com/llvm/llvm-project/pull/170945

When a PAuth ifunc is being used, we can represent any discriminator that
we want in the code and don't need to be restricted to 16 bits. For now we
only need this capability for address discriminated ptrauth expressions,
so keep the restriction in place for other discriminators.