Undo switch to type alias

This was pointless churn

Author: Aaron1011

src/librustc_metadata/rmeta/decoder/cstore_impl.rs

@@ -23,7 +23,6 @@ use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, CRATE_DEF_INDEX, LOCAL_CRATE}
 use rustc_span::source_map::{self, Span, Spanned};
 use rustc_span::symbol::Symbol;
 
-use rustc_ast::ast::Name;
 use rustc_data_structures::sync::Lrc;
 use smallvec::SmallVec;
 use std::any::Any;
@@ -387,7 +386,7 @@ pub fn provide(providers: &mut Providers<'_>) {
 }
 
 impl CStore {
-    pub fn struct_field_names_untracked(&self, def: DefId, sess: &Session) -> Vec<Spanned<Name>> {
+    pub fn struct_field_names_untracked(&self, def: DefId, sess: &Session) -> Vec<Spanned<Symbol>> {
         self.get_crate_data(def.krate).get_struct_field_names(def.index, sess)
     }