[clang] [clang-repl] Extend the C support. (PR #89804)

[Vassil Vassilev via cfe-commits]

vgvassilev wrote:

@jasonmolenda, I struggled quite a bit in reproducing the test failures and everything but I have a fix. Thanks a lot for your time and I hope the fix works!

https://github.com/llvm/llvm-project/pull/89804