[clang] [Clang] Generate the GEP instead of adding AST nodes (PR #73730)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

I actually think bdos is more complicated: array bounds checking can handle arbitrary base expressions, so it doesn't need to examine the base expression at all.  bdos can't do that, so more work is required to handle precisely the cases you want to handle.

https://github.com/llvm/llvm-project/pull/73730