Auto merge of #83592 - nagisa:nagisa/dso_local, r=davidtwco

Auto merge of #83592 - nagisa:nagisa/dso_local, r=davidtwco

Set dso_local for hidden, private and local items

This should probably have no real effect in most cases, as e.g. `hidden`
visibility already implies `dso_local` (or at least LLVM IR does not
preserve the `dso_local` setting if the item is already `hidden`), but
it should fix `-Crelocation-model=static` and improve codegen in
executables.

Note that this PR does not exhaustively port the logic in [clang], only the
portion that is necessary to fix a regression from LLVM 12 that relates to
`-Crelocation_model=static`.

Fixes #83335

[clang]: https://github.com/llvm/llvm-project/blob/3001d080c813da20b329303bf8f45451480e5905/clang/lib/CodeGen/CodeGenModule.cpp#L945-L1039