Bump up the MaxDepth in the BalancedDelimiterTracker.

The Avida Project (http://avida.devosoft.org) exceeds the 256 limit.
rdar://11289131

llvm-svn: 155737

clang/include/clang/Parse/Parser.h

@@ -451,7 +451,7 @@ private:
       }
     }
     
-    enum { MaxDepth = 256 };
+    enum { MaxDepth = 512 };
     
     bool diagnoseOverflow();
     bool diagnoseMissingClose();