[clang] [CIR] Fix void ternary operators- (PR #184691)

[Erich Keane via cfe-commits]

erichkeane wrote:

Test failures are unrelated, but fixed here: https://github.com/llvm/llvm-project/pull/184699

I'll do a update-branch once that gets merged.

https://github.com/llvm/llvm-project/pull/184691