function setInt16( arr, idx, value ) {
	arr[ idx ] = value;
}
Sets an element in an `Int16Array`.

@private
@param {Int16Array} arr - input array
@param {NonNegativeInteger} idx - element index
@param {number} value - value to set

@example
var Int16Array = require( '@stdlib/array/int16' );

var arr = new Int16Array( 4 );

setInt16( arr, 2, 3 );

var v = arr[ 2 ];
// returns 3