[Bug #21345] Fix accepting multiple rest patterns with leading match

Related:
* https://bugs.ruby-lang.org/issues/20765
* #2915

Author: Earlopain

src/prism.c

@@ -13123,14 +13123,6 @@ match8(const pm_parser_t *parser, pm_token_type_t type1, pm_token_type_t type2,
     return match1(parser, type1) || match1(parser, type2) || match1(parser, type3) || match1(parser, type4) || match1(parser, type5) || match1(parser, type6) || match1(parser, type7) || match1(parser, type8);
 }
 
-/**
- * Returns true if the current token is any of the nine given types.
- */
-static inline bool
-match9(const pm_parser_t *parser, pm_token_type_t type1, pm_token_type_t type2, pm_token_type_t type3, pm_token_type_t type4, pm_token_type_t type5, pm_token_type_t type6, pm_token_type_t type7, pm_token_type_t type8, pm_token_type_t type9) {
-    return match1(parser, type1) || match1(parser, type2) || match1(parser, type3) || match1(parser, type4) || match1(parser, type5) || match1(parser, type6) || match1(parser, type7) || match1(parser, type8) || match1(parser, type9);
-}
-
 /**
  * If the current token is of the specified type, lex forward by one token and
  * return true. Otherwise, return false. For example:
@@ -17675,7 +17667,7 @@ parse_pattern(pm_parser_t *parser, pm_constant_id_list_t *captures, uint8_t flag
         // Gather up all of the patterns into the list.
         while (accept1(parser, PM_TOKEN_COMMA)) {
             // Break early here in case we have a trailing comma.
-            if (match9(parser, PM_TOKEN_KEYWORD_THEN, PM_TOKEN_BRACE_RIGHT, PM_TOKEN_BRACKET_RIGHT, PM_TOKEN_PARENTHESIS_RIGHT, PM_TOKEN_SEMICOLON, PM_TOKEN_NEWLINE, PM_TOKEN_EOF,PM_TOKEN_KEYWORD_AND, PM_TOKEN_KEYWORD_OR)) {
+            if (match7(parser, PM_TOKEN_KEYWORD_THEN, PM_TOKEN_BRACE_RIGHT, PM_TOKEN_BRACKET_RIGHT, PM_TOKEN_PARENTHESIS_RIGHT, PM_TOKEN_SEMICOLON, PM_TOKEN_KEYWORD_AND, PM_TOKEN_KEYWORD_OR)) {
                 node = (pm_node_t *) pm_implicit_rest_node_create(parser, &parser->previous);
                 pm_node_list_append(&nodes, node);
                 trailing_rest = true;

test/prism/errors/pattern_match_implicit_rest.txt

@@ -0,0 +1,3 @@
+a=>b, *,
+        ^ expected a pattern expression after `,`
+