[clang] [clang] LazyOffsetPtr: Use native pointer width (PR #111995)

[Richard Smith via cfe-commits]

zygoloid wrote:

> > Can we remove `getAddressOfPointer` instead?. Where is it being used?
> 
> It is used in `VarDecl::getInitAddress()` in Decl.cpp. It looks like it is used indirectly by the StmtIterator

And that in turn is used in `StmtIterator`, and indeed we can end up *storing through* the type-punned `Stmt*` here:

https://github.com/llvm/llvm-project/blob/9930a5a3338ba642c52292107e0f729328d79034/clang/lib/Frontend/Rewrite/RewriteObjC.cpp#L4561

(and also in `RewriteModernObjC.cpp`). Are the ObjC rewriters still in use? Can we remove them? If not it looks like we'll need to do some substantial rewrites.

https://github.com/llvm/llvm-project/pull/111995