[llvm] [X86] [NFC] Prefer isa_and_nonnull (PR #99367)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

Should we really prefer this? The old form is shorter and no less clear.

(Relatedly: Should those isa checks be there at all? Is this intentionally excluding invokes?)

https://github.com/llvm/llvm-project/pull/99367