Rollup merge of #125381 - estebank:issue-96799, r=petrochenkov

Silence some resolve errors when there have been glob import errors

When encountering `use foo::*;` where `foo` fails to be found, and we later encounter resolution errors, we silence those later errors.

A single case of the above, for an *existing* import on a big codebase would otherwise have a huge number of knock-down spurious errors.

Ideally, instead of a global flag to silence all subsequent resolve errors, we'd want to introduce an unnameable binding in the appropriate rib as a sentinel when there's a failed glob import, so when we encounter a resolve error we can search for that sentinel and if found, and only then, silence that error. The current approach is just a quick proof of concept to iterate over.

Partially address #96799.

compiler/rustc_resolve/src/late.rs

@@ -4033,9 +4033,12 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     }
 
     #[inline]
-    /// If we're actually rustdoc then avoid giving a name resolution error for `cfg()` items.
+    /// If we're actually rustdoc then avoid giving a name resolution error for `cfg()` items or
+    // an invalid `use foo::*;` was found, which can cause unbounded ammounts of "item not found"
+    // errors. We silence them all.
     fn should_report_errs(&self) -> bool {
         !(self.r.tcx.sess.opts.actually_rustdoc && self.in_func_body)
+            && !self.r.glob_error.is_some()
     }
 
     // Resolve in alternative namespaces if resolution in the primary namespace fails.