[llvm-branch-commits] [clang] [Serialization] Code cleanups and polish 83233 (PR #83237)

[Ilya Biryukov via llvm-branch-commits]

ilya-biryukov wrote:

We've hit only one correctness issue that we don't yet have a reproducer for, but it gives this error:
```shell
Eigen/.../plugins/CommonCwiseBinaryOps.inc:47:29: error: inline function 'Eigen::operator*<float>' is not defined [-Werror,-Wundefined-inline]
```
I'll be on vacation for the next two weeks, @usx95 may be able to provide a reproducer in the meanwhile.
Maybe you'll have ideas on why it's happening without the reproducer too.

More importantly, we have seen quite a few compile actions becoming much slower and causing timeouts.
@alexfh is trying to profile the compile actions to find which functions are the bottleneck and will report the results here.

https://github.com/llvm/llvm-project/pull/83237