Keep track of parse errors in mods and don't emit resolve errors for paths involving them

When we expand a `mod foo;` and parse `foo.rs`, we now track whether that file had an unrecovered parse error that reached the end of the file. If so, we keep that information around. When resolving a path like `foo::bar`, we do not emit any errors for "`bar` not found in `foo`", as we know that the parse error might have caused `bar` to not be parsed and accounted for.

When this happens in an existing project, every path referencing `foo` would be an irrelevant compile error. Instead, we now skip emitting anything until `foo.rs` is fixed. Tellingly enough, we didn't have any test for errors caused by `mod` expansion.

Fix rust-lang#97734.

Author: estebank

clippy_lints/src/duplicate_mod.rs

@@ -63,7 +63,7 @@ impl_lint_pass!(DuplicateMod => [DUPLICATE_MOD]);
 
 impl EarlyLintPass for DuplicateMod {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
-        if let ItemKind::Mod(_, ModKind::Loaded(_, Inline::No, mod_spans)) = &item.kind
+        if let ItemKind::Mod(_, ModKind::Loaded(_, Inline::No, mod_spans, _)) = &item.kind
             && let FileName::Real(real) = cx.sess().source_map().span_to_filename(mod_spans.inner_span)
             && let Some(local_path) = real.into_local_path()
             && let Ok(absolute_path) = local_path.canonicalize()

clippy_lints/src/excessive_nesting.rs

@@ -163,7 +163,7 @@ impl Visitor<'_> for NestingVisitor<'_, '_> {
         }
 
         match &item.kind {
-            ItemKind::Trait(_) | ItemKind::Impl(_) | ItemKind::Mod(.., ModKind::Loaded(_, Inline::Yes, _)) => {
+            ItemKind::Trait(_) | ItemKind::Impl(_) | ItemKind::Mod(.., ModKind::Loaded(_, Inline::Yes, _, _)) => {
                 self.nest_level += 1;
 
                 if !self.check_indent(item.span, item.id) {

clippy_utils/src/ast_utils.rs

@@ -379,7 +379,7 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
         (Mod(lu, lmk), Mod(ru, rmk)) => {
             lu == ru
                 && match (lmk, rmk) {
-                    (ModKind::Loaded(litems, linline, _), ModKind::Loaded(ritems, rinline, _)) => {
+                    (ModKind::Loaded(litems, linline, _, _), ModKind::Loaded(ritems, rinline, _, _)) => {
                         linline == rinline && over(litems, ritems, |l, r| eq_item(l, r, eq_item_kind))
                     },
                     (ModKind::Unloaded, ModKind::Unloaded) => true,