[clang] [clang-tools-extra] [clang][modules] Serialize `CodeGenOptions` (PR #146422)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> I'm not suggesting to treat CodeGenOptions as incompatible by default. For now I'm just trying to remove the duplication and improve the infrastructure.CodeGenOptions are still benign by default, and can only be marked as compatible, which doesn't have any impact on explicitly-built modules. This PR is intended to be an NFC.

Then it sounds good to me.

https://github.com/llvm/llvm-project/pull/146422