[clang] [CIR][WIP] Make BeginCatchOp target-independent (PR #190612)

[Amr Hesham via cfe-commits]

AmrDeveloper wrote:

Notes:

- I am looking for early feedback on the approach, for the BeginCatchKind, the names are placeholders for now.
- I will update the docs once the design of the op is finished.
- IR for different targets: https://godbolt.org/z/3avqsj31M

https://github.com/llvm/llvm-project/pull/190612