MCOL-4409 This patch combines VDecimal and Decimal and makes
IDB_Decimal an alias for the result class
MCOL-4409 More boilerplate reduction in Func_mod
Removed couple TSInt128::toType() methods
In addition, a regression in a WHERE clause with a WF field
as the LHS and an addition operation on two WF fields on the RHS
is also fixed. The issue was SimpleColumn::getDecimalVal() was
setting precision = 19, with the value of one of the operands of the
addition operation being set in VDecimal::value instead of
VDecimal::s128Value. addSubtractExecute() in mcs_decimal.cpp makes the
assumption that if precision > 18 and precision <= 38, we need to
fetch the wide s128Value, not the narrow value field. So we are
fixing the precision set in SimpleColumn::getDecimalVal().
For the initial BLOB/TEXT pull request we put them in the same bucket as
VARBINARY, forcing many functions to be disabled. This patch enables the
same TEXT function support as VARCHAR.
