[clang] [Sema] Compare canonical conversion function (PR #154158)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> > > With lazy template loading, it is possible to find non-canonical FunctionDecls
> > 
> > 
> > But this may be concerning. Do you feel this may cause more problem?
> 
> Of course this can result in more problems like the one fixed here. That is the box we opened with lazy loading of template instantiations.

let's wait for the testing response from @emaxx-google and @ilya-biryukov 

https://github.com/llvm/llvm-project/pull/154158