flang] Fix crash in semantic error recovery situation

[klausler]

Summary

[A CHECK() in semantics is triggering when analyzing a program
with an undefined derived type pointer because the CHECK is
expecting a new error message to have been issued in a function
but not allowing for the case that a diagnostic could have been
produced earlier. Adjust the predicate.

[PeteSteinfeld]

Looks great!

flang/lib/Semantics/expression.cpp

if (const Symbol * sym{sc.component.symbol}) {
                 ProcedureDesignator{*sym}, std::move(arguments)};
           }
         }
       }
       Say(sc.component.source,
           "Base of procedure component reference is not a derived-type object"_err_en_US);
     }
   }
-  CHECK(!GetContextualMessages().empty());
+  CHECK(context_.AnyFatalError());
   return std::nullopt;
 }
 
 // Can actual be argument associated with dummy?
 static bool CheckCompatibleArgument(bool isElemental,
     const ActualArgument &actual, const characteristics::DummyArgument &dummy) {
   const auto *expr{actual.UnwrapExpr()};
   return std::visit(