delegation(small cleanup): remove not needed PhantomData

compiler/rustc_ast_lowering/src/delegation.rs

@@ -37,7 +37,6 @@
 //! also be emitted during HIR ty lowering.
 
 use std::iter;
-use std::marker::PhantomData;
 
 use ast::visit::Visitor;
 use hir::def::{DefKind, PartialRes, Res};
@@ -420,7 +419,6 @@ impl<'hir, R: ResolverAstLoweringExt<'hir>> LoweringContext<'_, 'hir, R> {
                         resolver: this.resolver,
                         path_id: delegation.id,
                         self_param_id: pat_node_id,
-                        phantom: PhantomData,
                     };
                     self_resolver.visit_block(block);
                     // Target expr needs to lower `self` path.
@@ -673,14 +671,13 @@ impl<'hir, R: ResolverAstLoweringExt<'hir>> LoweringContext<'_, 'hir, R> {
     }
 }
 
-struct SelfResolver<'a, 'tcx, R> {
+struct SelfResolver<'a, R> {
     resolver: &'a mut R,
     path_id: NodeId,
     self_param_id: NodeId,
-    phantom: PhantomData<&'tcx ()>,
 }
 
-impl<'tcx, R: ResolverAstLoweringExt<'tcx>> SelfResolver<'_, 'tcx, R> {
+impl<'tcx, R: ResolverAstLoweringExt<'tcx>> SelfResolver<'_, R> {
     fn try_replace_id(&mut self, id: NodeId) {
         if let Some(res) = self.resolver.get_partial_res(id)
             && let Some(Res::Local(sig_id)) = res.full_res()
@@ -692,7 +689,7 @@ impl<'tcx, R: ResolverAstLoweringExt<'tcx>> SelfResolver<'_, 'tcx, R> {
     }
 }
 
-impl<'ast, 'a, 'tcx, R: ResolverAstLoweringExt<'tcx>> Visitor<'ast> for SelfResolver<'a, 'tcx, R> {
+impl<'ast, 'tcx, R: ResolverAstLoweringExt<'tcx>> Visitor<'ast> for SelfResolver<'_, R> {
     fn visit_id(&mut self, id: NodeId) {
         self.try_replace_id(id);
     }