[clang] [Clang][CodeGen] Do not set inbounds flag for struct GEP with null base pointers (PR #130734)

[Yingwei Zheng via cfe-commits]

dtcxzyw wrote:

Rebased on the top of https://github.com/llvm/llvm-project/pull/134269 and https://github.com/llvm/llvm-project/pull/134221

https://github.com/llvm/llvm-project/pull/130734