Remove unused derives

src/librustc/lint/builtin.rs

@@ -516,7 +516,7 @@ declare_lint_pass! {
 
 // this could be a closure, but then implementing derive traits
 // becomes hacky (and it gets allocated)
-#[derive(PartialEq, RustcEncodable, RustcDecodable, Debug)]
+#[derive(PartialEq)]
 pub enum BuiltinLintDiagnostics {
     Normal,
     BareTraitObject(Span, /* is_global */ bool),

src/librustc/lint/context.rs

@@ -66,7 +66,7 @@ pub struct LintStore {
 
 /// Lints that are buffered up early on in the `Session` before the
 /// `LintLevels` is calculated
-#[derive(PartialEq, Debug)]
+#[derive(PartialEq)]
 pub struct BufferedEarlyLint {
     pub lint_id: LintId,
     pub ast_id: ast::NodeId,