[clang] [Clang] Use ConstantExpr::getGetElementPtr() with DataLayout (PR #225415)

[Nikita Popov via cfe-commits]

nikic wrote:

I landed the clang-format fix separately in https://github.com/llvm/llvm-project/pull/225621, because it touched a larger section of code.

Also a followup in https://github.com/llvm/llvm-project/pull/225624 to fix a test depending on the used testing triple.

https://github.com/llvm/llvm-project/pull/225415