function repeat( str, n ) {
	return builtin.call( str, n );
}
Repeats a string a specified number of times and returns the concatenated result.

@param {string} str - string to repeat
@param {NonNegativeInteger} n - number of times to repeat the string
@returns {string} repeated string

@example
var str = repeat( 'a', 5 );
// returns 'aaaaa'

@example
var str = repeat( '', 100 );
// returns ''

@example
var str = repeat( 'beep', 0 );
// returns ''