function labelXPos( orient, range ) {
	if ( orient === 'left' || orient === 'right' ) {
		return -range[0] / 2;
	}
	return range[1] / 2;
}
Returns the label `x` coordinate.

@private
@param {string} orient - axis orientation
@param {NumericArray} range - scale range
@returns {number} `x` coordinate