[clang] [clang][bytecode] Bail out from type-punning casts (PR #163809)

[Timm Baeder via cfe-commits]

tbaederr wrote:

Looking at https://godbolt.org/z/xoM5Tb7cc, I think we should basically reject `CK_BitCast` casts where the pointee types don't qualify to the same `PrimType`. That's just from a quick glance though, I haven't checked if that breaks anything.

https://github.com/llvm/llvm-project/pull/163809