Rollup merge of #140617 - Urgau:unsafe_attr-lint-allow, r=jieyouxu

Report the `unsafe_attr_outside_unsafe` lint at the closest node

This PR have `AstValidation` track a linting node id and then uses it when reporting the `unsafe_attr_outside_unsafe` lint, so that instead of being bound at the crate-root, `#[allow]` of the lint works at any node.

Fixes rust-lang/rust#140602
r? `@jieyouxu`

tests/ui/rust-2024/unsafe-attributes/unsafe-attributes-allow.rs

@@ -0,0 +1,16 @@
+//@ check-pass
+//@ edition: 2021
+//
+// Anti-regression test for https://github.com/rust-lang/rust/issues/140602
+// where the generated warning couldn't be allowed due too being attached to
+// the wrong AST node.
+
+#![deny(unsafe_attr_outside_unsafe)]
+
+#[allow(unsafe_attr_outside_unsafe)]
+mod generated {
+    #[no_mangle]
+    fn _generated_foo() {}
+}
+
+fn main() {}