Add tf_control type and allow $ in bare-id.

* Add tf_control as primitive type;
* Allow $ in bare-id to allow attributes with $ (to make it trivially to mangle a TF attribute);

PiperOrigin-RevId: 206342642
diff --git a/lib/Parser/Parser.cpp b/lib/Parser/Parser.cpp
index 11850ea..71737ce 100644
--- a/lib/Parser/Parser.cpp
+++ b/lib/Parser/Parser.cpp
@@ -281,6 +281,9 @@
   case Token::kw_affineint:
     consumeToken(Token::kw_affineint);
     return builder.getAffineIntType();
+  case Token::kw_tf_control:
+    consumeToken(Token::kw_tf_control);
+    return builder.getTFControlType();
   case Token::inttype: {
     auto width = getToken().getIntTypeBitwidth();
     if (!width.hasValue())