* add `{u,s}{add,sub,mul}_overflow` with interpreter
* add `{u,s}{add,sub,mul}_overflow` for x64
* add `{u,s}{add,sub,mul}_overflow` for aarch64
* 128bit filetests for `{u,s}{add,sub,mul}_overflow`
* `{u,s}{add,sub,mul}_overflow` emit tests for x64
* `{u,s}{add,sub,mul}_overflow` emit tests for aarch64
* Initial review changes
* add `with_flags_extended` helper
* add `with_flags_chained` helper