absolute Value
Returns the absolute value of this half-precision float. Special values are handled in the following ways:
If the specified half-precision float is NaN, the result is NaN
If the specified half-precision float is zero (negative or positive), the result is positive zero (see POSITIVE_ZERO)
If the specified half-precision float is infinity (negative or positive), the result is positive infinity (see POSITIVE_INFINITY)
Return
The absolute value of the specified half-precision float