[clang] [CIR] Lowering __builtin_stdc_* calls (PR #214931)

[Kunal Dubey via cfe-commits]

xakep8 wrote:

@bcardosolopes I think with this PR the issue #214443 will be fixed, should I change `Part of` to `Fixes` to close the issue with this merge?

https://github.com/llvm/llvm-project/pull/214931