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

[Vassil Vassilev via cfe-commits]

vgvassilev wrote:

The bots fail on windows due to `TEST 'Clang :: CoverageMapping/mcdc-system-headers.cpp' FAILED` which does not seem related to this PR.

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