Make BIGINT type hack for compatible with the old Koski-based parser configurable

[ViggoC]

In DuckParser.cpp, parseConstantExpr hard code the transform from INTEGER to BIGINT for compatibility reason. This is inconsistent with the behavior of most SQL engine. Is Koski parser still used in this project? Can we make is configurable or just remove it?

  // This is a hack to make DuckDB more compatible with the old Koski-based
  // parser. By default literal integer constants in DuckDB parser are INTEGER,
  // while in Koski parser they were BIGINT.
  if (value.type().id() == LogicalTypeId::INTEGER) {
    value = Value::BIGINT(value.GetValue<int32_t>());
  }

[mbasmanova]

@ViggoC We can try removing it or hiding behind a new flag in ParseOptions. Would you like to work on this?

struct ParseOptions {
  // Retain legacy behavior by default.
  bool parseDecimalAsDouble = true;

  bool parseIntegerAsBigint = true;
};

[ViggoC]

Sure, I can work on it.

[mbasmanova]

CC: @majetideepak