Also store Parser paren numbers; likely fixes ROOT-6976:

The parser (or rather the BalancedDelimiterTracker) was doing a Parser::cutOffParsing() because
of an overflow of open ( - because we never reset the count.

Author: Axel-Naumann

clang/include/clang/Parse/Parser.h

@@ -24,6 +24,8 @@
 #include <optional>
 #include <stack>
 
+namespace cling { class ParserStateRAII; }
+
 namespace clang {
   class PragmaHandler;
   class Scope;
@@ -63,6 +65,7 @@ class Parser : public CodeCompletionHandler {
   friend class ParenBraceBracketBalancer;
   friend class BalancedDelimiterTracker;
   friend class DestroyTemplateIdAnnotationsRAIIObj;
+  friend class ::cling::ParserStateRAII;
 
   Preprocessor &PP;