Auto merge of #56051 - pietroalbini:rollup, r=pietroalbini

Rollup of 25 pull requests

Successful merges:

 - #55562 (Add powerpc- and powerpc64-unknown-linux-musl targets)
 - #55564 (test/linkage-visibility: Ignore on musl targets)
 - #55827 (A few tweaks to iterations/collecting)
 - #55834 (Forward the ABI of the non-zero sized fields of an union if they have the same ABI)
 - #55857 (remove unused dependency)
 - #55862 (in which the E0618 "expected function" diagnostic gets a makeover)
 - #55867 (do not panic just because cargo failed)
 - #55894 (miri enum discriminant handling: Fix treatment of pointers, better error when it is undef)
 - #55916 (Make miri value visitor useful for mutation)
 - #55919 (core/tests/num: Simplify `test_int_from_str_overflow()` test code)
 - #55923 (reword #[test] attribute error on fn items)
 - #55949 (ty: return impl Iterator from Predicate::walk_tys)
 - #55952 (Update to Clang 7 on CI.)
 - #55953 (#53488 Refactoring UpvarId)
 - #55962 (rustdoc: properly calculate spans for intra-doc link resolution errors)
 - #55963 (Stress test for MPSC)
 - #55968 (Clean up some non-mod-rs stuff.)
 - #55970 (Miri backtrace improvements)
 - #56007 (CTFE: dynamically make sure we do not call non-const-fn)
 - #56011 (Replace data.clone() by Arc::clone(&data) in mutex doc.)
 - #56012 (avoid shared ref in UnsafeCell::get)
 - #56016 (Add VecDeque::resize_with)
 - #56027 (docs: Add missing backtick in object_safety.rs docs)
 - #56043 (remove "approx env bounds" if we already know from trait)
 - #56059 (Increase `Duration` approximate equal threshold to 1us)

2 files changed, 9 insertions, 11 deletions

diff --git a/src/libsyntax_ext/deriving/generic/mod.rs b/src/libsyntax_ext/deriving/generic/mod.rs
index 2f6b306e8f8..a5b12ce4c4d 100644
--- a/src/libsyntax_ext/deriving/generic/mod.rs
+++ b/src/libsyntax_ext/deriving/generic/mod.rs
@@ -1200,16 +1200,14 @@ impl<'a> MethodDef<'a> {
         let sp = trait_.span;
         let variants = &enum_def.variants;
 
-        let self_arg_names = self_args.iter()
-            .enumerate()
-            .map(|(arg_count, _self_arg)| {
-                if arg_count == 0 {
-                    "__self".to_string()
-                } else {
+        let self_arg_names = iter::once("__self".to_string()).chain(
+            self_args.iter()
+                .enumerate()
+                .skip(1)
+                .map(|(arg_count, _self_arg)|
                     format!("__arg_{}", arg_count)
-                }
-            })
-            .collect::<Vec<String>>();
+                )
+            ).collect::<Vec<String>>();
 
         let self_arg_idents = self_arg_names.iter()
             .map(|name| cx.ident_of(&name[..]))
@@ -1218,7 +1216,7 @@ impl<'a> MethodDef<'a> {
         // The `vi_idents` will be bound, solely in the catch-all, to
         // a series of let statements mapping each self_arg to an int
         // value corresponding to its discriminant.
-        let vi_idents: Vec<ast::Ident> = self_arg_names.iter()
+        let vi_idents = self_arg_names.iter()
             .map(|name| {
                 let vi_suffix = format!("{}_vi", &name[..]);
                 cx.ident_of(&vi_suffix[..]).gensym()
diff --git a/src/libsyntax_ext/test.rs b/src/libsyntax_ext/test.rs
index be3485cfa7c..b8a171b52ad 100644
--- a/src/libsyntax_ext/test.rs
+++ b/src/libsyntax_ext/test.rs
@@ -53,7 +53,7 @@ pub fn expand_test_or_bench(
         if let Annotatable::Item(i) = item { i }
         else {
             cx.parse_sess.span_diagnostic.span_fatal(item.span(),
-                "#[test] attribute is only allowed on fn items").raise();
+                "#[test] attribute is only allowed on non associated functions").raise();
         };
 
     if let ast::ItemKind::Mac(_) = item.node {