Auto merge of #37824 - jseyfried:symbols, r=eddyb

Clean up `ast::Attribute`, `ast::CrateConfig`, and string interning

This PR
 - removes `ast::Attribute_` (changing `Attribute` from `Spanned<Attribute_>` to a struct),
 - moves a `MetaItem`'s name from the `MetaItemKind` variants to a field of `MetaItem`,
 - avoids needlessly wrapping `ast::MetaItem` with `P`,
 - moves string interning into `syntax::symbol` (`ast::Name` is a reexport of `symbol::Symbol` for now),
 - replaces `InternedString` with `Symbol` in the AST, HIR, and various other places, and
 - refactors `ast::CrateConfig` from a `Vec` to a `HashSet`.

r? @eddyb

1 files changed, 2 insertions, 1 deletions

diff --git a/src/test/run-make/issue-19371/foo.rs b/src/test/run-make/issue-19371/foo.rs
index ed127b017b6..0336fe277c5 100644
--- a/src/test/run-make/issue-19371/foo.rs
+++ b/src/test/run-make/issue-19371/foo.rs
@@ -25,6 +25,7 @@ use rustc_driver::driver::{compile_input, CompileController, anon_src};
 use rustc_metadata::cstore::CStore;
 use rustc_errors::registry::Registry;
 
+use std::collections::HashSet;
 use std::path::PathBuf;
 use std::rc::Rc;
 
@@ -65,7 +66,7 @@ fn basic_sess(sysroot: PathBuf) -> (Session, Rc<CStore>) {
 
 fn compile(code: String, output: PathBuf, sysroot: PathBuf) {
     let (sess, cstore) = basic_sess(sysroot);
-    let cfg = build_configuration(&sess, vec![]);
+    let cfg = build_configuration(&sess, HashSet::new());
     let control = CompileController::basic();
     let input = Input::Str { name: anon_src(), input: code };
     compile_input(&sess, &cstore, &input, &None, &Some(output), None, &control);