[clang] [clang-tools-extra] [llvm] [clang]: reflection operator parsing for global namespace and primitive types (PR #164692)

[Chuanqi Xu via llvm-commits]

ChuanqiXu9 wrote:

> > > > > If reflection is 'experimental' anything we change that breaks serialization/etc is perfectly fine.
> > > > 
> > > > 
> > > > If this is the decision, I think it will be better to explicitly diagnose for any code path that triggers serialization
> > > 
> > > 
> > > That seems pretty novel? We don't typically diagnose that sort of thing.
> > 
> > 
> > I just think, if users triggers serialization with reflection now, it is better to diagnose immediately instead of continue silently and the user may meet odd problems...
> 
> Typically we count on the 'experimental' word in the flag to warn that. Do we otherwise diagnose in serialization? I'd rather us not try to do something new there.

I just want to offer more info for users so that they can understand the status better and not confusing. This is a suggestion not a requirement.

https://github.com/llvm/llvm-project/pull/164692