[llvm] [Support] Extend ExtensibleRTTI utility to support basic multiple inheritance. (PR #112643)

[David Blaikie via llvm-commits]

https://github.com/dwblaikie approved this pull request.

Re:single/first base class gets to expose it's non-defsult ctor and all other bases must have default ctors - sounds ok for a first pass.



https://github.com/llvm/llvm-project/pull/112643