Avoid extracting default alias for extras

Fixes tree-sitter#1834

Author: nmote

cli/src/generate/prepare_grammar/extract_default_aliases.rs

@@ -62,6 +62,18 @@ pub(super) fn extract_default_aliases(
         }
     }
 
+    for symbol in syntax_grammar.extra_symbols.iter() {
+        let mut status = match symbol.kind {
+            SymbolType::External => &mut external_status_list[symbol.index],
+            SymbolType::NonTerminal => &mut non_terminal_status_list[symbol.index],
+            SymbolType::Terminal => &mut terminal_status_list[symbol.index],
+            SymbolType::End | SymbolType::EndOfNonTerminalExtra => {
+                panic!("Unexpected end token")
+            }
+        };
+        status.appears_unaliased = true;
+    }
+
     let symbols_with_statuses = (terminal_status_list
         .iter_mut()
         .enumerate()

test/fixtures/test_grammars/aliased_rules/corpus.txt

@@ -7,7 +7,7 @@ Method calls
 ---
 
 (statement
-  (star_aliased)
+  (star)
   (call_expression
     (member_expression
       (variable_name)