Update compiler/rustc_expand/src/mbe/quoted.rs

Co-authored-by: Michael Goulet <[email protected]>

Author: eholk

compiler/rustc_expand/src/mbe/quoted.rs

@@ -13,8 +13,8 @@ use crate::mbe::macro_parser::count_metavar_decls;
 use crate::mbe::{Delimited, KleeneOp, KleeneToken, MetaVarExpr, SequenceRepetition, TokenTree};
 
 pub(crate) const VALID_FRAGMENT_NAMES_MSG: &str = "valid fragment specifiers are \
-    `ident`, `block`, `stmt`, `expr`, `expr_2021`, `pat`, `ty`, `lifetime`, `literal`, `path`, \
-    `meta`, `tt`, `item` and `vis`";
+    `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, \
+    `meta`, `tt`, `item` and `vis`, along with `expr_2021` and `pat_param` for edition compatibility";
 
 /// Takes a `tokenstream::TokenStream` and returns a `Vec<self::TokenTree>`. Specifically, this
 /// takes a generic `TokenStream`, such as is used in the rest of the compiler, and returns a