bpo-43822: Improve syntax errors for missing commas (GH-25377)

diff --git a/Parser/token.c b/Parser/token.c
index a489668..74bca0e 100644
--- a/Parser/token.c
+++ b/Parser/token.c
@@ -65,6 +65,7 @@ const char * const _PyParser_TokenNames[] = {
     "ASYNC",
     "TYPE_IGNORE",
     "TYPE_COMMENT",
+    "SOFT_KEYWORD",
     "<ERRORTOKEN>",
     "<COMMENT>",
     "<NL>",