fix links in doc comments

Author: mark-i-m

compiler/rustc_ast/src/token.rs

@@ -718,7 +718,7 @@ pub enum NonterminalKind {
 }
 
 /// Used when parsing a non-terminal (see `parse_nonterminal`) to determine if `:pat` should match
-/// `top_pat` or `pat<no_top_alt>`. See issue https://github.com/rust-lang/rust/pull/78935.
+/// `top_pat` or `pat<no_top_alt>`. See issue <https://github.com/rust-lang/rust/pull/78935>.
 pub enum OrPatNonterminalMode {
     TopPat,
     NoTopAlt,

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -422,7 +422,7 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
 /// previously be a separator that follows `:pat`. Thus, we make a special case to parse `:pat` the
 /// old way if it happens to be followed by `|` in the matcher.
 ///
-/// See https://github.com/rust-lang/rust/issues/54883 for more info.
+/// See <https://github.com/rust-lang/rust/issues/54883> for more info.
 fn or_pat_mode(item: &MatcherPosHandle<'_, '_>) -> OrPatNonterminalMode {
     if item.idx < item.top_elts.len() - 1 {
         // Look at the token after the current one to see if it is `|`.