inherent_to_string: Check HIR tree before checking for macros.

Author: Jarcho

clippy_lints/src/inherent_to_string.rs

@@ -91,10 +91,6 @@ declare_lint_pass!(InherentToString => [INHERENT_TO_STRING, INHERENT_TO_STRING_S
 
 impl<'tcx> LateLintPass<'tcx> for InherentToString {
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
-        if impl_item.span.from_expansion() {
-            return;
-        }
-
         // Check if item is a method called `to_string` and has a parameter 'self'
         if let ImplItemKind::Fn(ref signature, _) = impl_item.kind
             // #11201
@@ -106,6 +102,7 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
             && decl.implicit_self.has_implicit_self()
             && decl.inputs.len() == 1
             && impl_item.generics.params.iter().all(|p| matches!(p.kind, GenericParamKind::Lifetime { .. }))
+            && !impl_item.span.from_expansion()
             // Check if return type is String
             && is_type_lang_item(cx, return_ty(cx, impl_item.owner_id), LangItem::String)
             // Filters instances of to_string which are required by a trait