upgrade syntax submodule

bobzhang · bobzhang · commit 35996331060d · 2020-12-06T14:43:29.000+08:00
diff --git a/syntax b/syntax
@@ -1 +1 @@
-Subproject commit 7f5c9680883f4e5b7c9958e77b954d5637e651d8
+Subproject commit 7cc70c947c35357f71e24920c0e0c4cb58493125
