[clang] WIP: [clang] MicrosoftCXXABI: Fix exception copy constructor LUT after loading AST (PR #114075)

[Reid Kleckner via cfe-commits]

https://github.com/rnk commented:

I think @majnemer added the lookup table originally. I think we did things this way because, while it creates obvious serialization problems, it's the most straightforwardly correct approach if you think finding copy constructors is an ambiguous operation. It's concerning that there isn't a straightforward CXXRecordDecl::getCopyConstructorIfItExists method, and I seem to recall I've had to work around this before in other contexts like debug info.

https://github.com/llvm/llvm-project/pull/114075