Rollup merge of #99483 - compiler-errors:issue-99482, r=jyn514

Fix a numerical underflow in tuple wrap suggestion

Fixes #99482

I'm a clown, I rewrote the arg mismatch algo to use well-typed indices to avoid things like this, but then I added my own indexing bug, lol.

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -573,6 +573,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // If so, we might have just forgotten to wrap some args in a tuple.
             if let Some(ty::Tuple(tys)) =
                 formal_and_expected_inputs.get(mismatch_idx.into()).map(|tys| tys.1.kind())
+                // If the tuple is unit, we're not actually wrapping any arguments.
+                && !tys.is_empty()
                 && provided_arg_tys.len() == formal_and_expected_inputs.len() - 1 + tys.len()
             {
                 // Wrap up the N provided arguments starting at this position in a tuple.