Warn on pointless `#[derive]` in more places

This fixes the regression in #49934 and ensures that unused `#[derive]`s on statements, expressions and generic type parameters survive to trip the `unused_attributes` lint. For `#[derive]` on macro invocations it has a hardcoded warning since linting occurs after expansion. This also adds regression testing for some nodes that were already warning properly.

closes #49934

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 91c9a1524e1..46e3e20f58e 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -821,7 +821,7 @@ impl Stmt {
 
     pub fn is_item(&self) -> bool {
         match self.node {
-            StmtKind::Local(_) => true,
+            StmtKind::Item(_) => true,
             _ => false,
         }
     }