[php-src] PR #23618: Fix GH-23552: keyword class constant name not retagged to T_STRING

Pull Request: https://github.com/php/php-src/pull/23618 Author: iliaal class F { const NEW = Bar::NEW; } reported T_NEW for the declared name under token_get_all($code, TOKEN_PARSE). The tokenizer resolved a parser feedback by searching the collected token list backwards for a matching token text, and since 8.3 typed class constants defer reducing the constant name past the initializer scan, so the declaration's feedback re-found the initializer's token. Matching the ident's source offset instead also corrects const NEW = NEW Bar();, where the text search retagged the NEW operator and left the declaration alone. The offset is accumulated as tokens are emitted rather than derived from LANG_SCNG(yy_cursor). The unterminated-comment rule returns T_ERROR before recomputing yyleng, so the cursor overshoots the emitted length there; the test pins that input. Fixes #23552