Fix nits

Author: yaahc

chalk-derive/src/lib.rs

@@ -34,10 +34,7 @@ pub fn derive_fold(item: TokenStream) -> TokenStream {
                     &self,
                     folder: &mut dyn Folder < 'i, #arg, #arg >,
                     binders: usize,
-                ) -> ::chalk_engine::fallible::Fallible<Self::Result>
-                where
-                    #arg: 'i,
-                {
+                ) -> ::chalk_engine::fallible::Fallible<Self::Result> {
                     #body
                 }
             }

chalk-ir/src/lib.rs

@@ -952,16 +952,12 @@ pub struct ProgramClauseImplication<I: Interner> {
     pub conditions: Goals<I>,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, HasInterner)]
 pub enum ProgramClause<I: Interner> {
     Implies(ProgramClauseImplication<I>),
     ForAll(Binders<ProgramClauseImplication<I>>),
 }
 
-impl<I: Interner> HasInterner for ProgramClause<I> {
-    type Interner = I;
-}
-
 impl<I: Interner> ProgramClause<I> {
     pub fn into_from_env_clause(self, interner: &I) -> ProgramClause<I> {
         match self {