[clang] [Clang][CodeGen] Respect -fwrapv-pointer when emitting struct GEPs (PR #134269)

[Nikita Popov via cfe-commits]

nikic wrote:

Usually we'd want to also insert `-fsanitize=pointer-overflow` instrumentation in places where we respect `-fwrapv-pointer`. I'm not entirely sure whether we want to do this here, as it will probably blow up the amount of inserted instrumentation...

https://github.com/llvm/llvm-project/pull/134269