[clang] [CIR] Fixup tests after GEP type changed (PR #225770)

[Andrzej Warzyński via cfe-commits]

banach-space wrote:

Thanks for the fix, @erichkeane ! 

Next time it would be good to co-ordinate a bit more - I'm always worried that somebody is already fixing a regression that I am looking at. I suggest posting on Discord before sending a fix - are you following Discord?

https://github.com/llvm/llvm-project/pull/225770