rust private

save-analysis: use a fallback when access levels couldn't be computed Fixing an RLS regression I introduced in https://github.com/rust-lang/rust/pull/57343 :cry: I missed a case where we get [called back with analysis when type checking fails](https://github.com/rust-lang/rust/blob/9d54812829e9d92dac35a4a0f358cdc5a2475371/src/librustc_driver/driver.rs#L1264). Since privacy checking normally is done afterwards, when we execute the `privacy_access_levels` query inside the save_analysis callback we'll calculate it for the first time and since typeck info isn't complete, we'll crash there. Double-checked locally and it seems to have fixed the problem. r? @nikomatsakis