Update tokenize.cpp

Author: chrchr-github

lib/tokenize.cpp

@@ -8960,7 +8960,7 @@ void Tokenizer::findGarbageCode() const
         // count number of semicolons
         int semicolons = 0, colons = 0;
         const Token* const endTok = tok->linkAt(1);
-        for (tok = tok->tokAt(2); tok != endTok; tok = tok->next()) {
+        for (tok = tok->tokAt(2); tok && tok != endTok; tok = tok->next()) {
             if (const Token* lam = findLambdaEndTokenWithoutAST(tok)) {
                 tok = lam;
                 continue;