Introduced fDecimalOverflowCheck to enable/disable overflow check.
Add support into a FunctionColumn.
Low level scanning crashes on medium sized data sets.
2. Set Decimal precision in SimpleColumn::evaluate().
3. Add support for int128_t in ConstantColumn.
4. Set IDB_Decimal::s128Value in buildDecimalColumn().
5. Use width 16 as first if predicate for branching based on decimal width.