use codegen_instance_attrs where an instance is (easily) available

compiler/rustc_codegen_llvm/src/callee.rs

@@ -102,7 +102,7 @@ pub(crate) fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'t
         let is_hidden = if is_generic {
             // This is a monomorphization of a generic function.
             if !(cx.tcx.sess.opts.share_generics()
-                || tcx.codegen_fn_attrs(instance_def_id).inline
+                || tcx.codegen_instance_attrs(instance.def).inline
                     == rustc_attr_data_structures::InlineAttr::Never)
             {
                 // When not sharing generics, all instances are in the same