Performs a logical shift of the argument by the specified number of
decimal digits. Positive values of the second operand shift the argument
to the left; negative values shift the argument to the right.
If the argument is not a valid logical operand, or if the absolute value of
the shift is greater than precision, an INVALID_OPERATION is signaled.
Implements the 'shift' function in the specification. (p. 49)
Performs a logical shift of the argument by the specified number of decimal digits. Positive values of the second operand shift the argument to the left; negative values shift the argument to the right. If the argument is not a valid logical operand, or if the absolute value of the shift is greater than precision, an INVALID_OPERATION is signaled. Implements the 'shift' function in the specification. (p. 49)