Inline Parser::nonterminal_may_begin_with.

Author: nnethercote

compiler/rustc_parse/src/parser/nonterminal.rs

@@ -11,8 +11,10 @@ use crate::parser::{FollowedByType, ForceCollect, NtOrTt, Parser, PathStyle};
 impl<'a> Parser<'a> {
     /// Checks whether a non-terminal may begin with a particular token.
     ///
-    /// Returning `false` is a *stability guarantee* that such a matcher will *never* begin with that
-    /// token. Be conservative (return true) if not sure.
+    /// Returning `false` is a *stability guarantee* that such a matcher will *never* begin with
+    /// that token. Be conservative (return true) if not sure. Inlined because it has a single call
+    /// site.
+    #[inline]
     pub fn nonterminal_may_begin_with(kind: NonterminalKind, token: &Token) -> bool {
         /// Checks whether the non-terminal may contain a single (non-keyword) identifier.
         fn may_be_ident(nt: &token::Nonterminal) -> bool {