message: Deallocate prepared statement
diff: #include "duckdb/execution/operator/helper/physical_result_collector.hpp"
  #include "duckdb/parser/query_node/select_node.hpp"
  #include "duckdb/parser/parsed_expression_iterator.hpp"
  +#include "duckdb/parser/statement/drop_statement.hpp"
  #include "duckdb/parser/statement/prepare_statement.hpp"
  #include "duckdb/parser/statement/execute_statement.hpp"
  @@ -801,6 +802,7 @@ public:
  vector<unique_ptr<ParsedExpression>> values;
  unique_ptr<SQLStatement> prepare_statement;
  unique_ptr<SQLStatement> execute_statement;
  + unique_ptr<SQLStatement> dealloc_statement;
  public:
  void ConvertConstants(unique_ptr<ParsedExpression> &child) {
  @@ -847,8 +849,13 @@ public:
  execute->name = name;
  execute->values = move(values);
  + auto dealloc = make_unique<DropStatement>();
  + dealloc->info->type = CatalogType::PREPARED_STATEMENT;
  + dealloc->info->name = string(name);
  +
  prepare_statement = move(prepare);
  execute_statement = move(execute);
  + dealloc_statement = move(dealloc);
  }
  };
  @@ -994,6 +1001,8 @@ string ClientContext::VerifyQuery(ClientContextLock &lock, const string &query,
  results.push_back(make_unique<MaterializedQueryResult>(ex.what()));
  }
  }
  + RunStatementInternal(lock, string(), move(verifier.dealloc_statement), false, false);
  +
  interrupted = false;
  }
  config.enable_optimizer = optimizer_enabled;
  