Source

File: wp-includes/deprecated.php

function get_themes() {
	_deprecated_function( __FUNCTION__, '3.4.0', 'wp_get_themes()' );

	global $wp_themes;
	if ( isset( $wp_themes ) )
		return $wp_themes;

	$themes = wp_get_themes();
	$wp_themes = array();

	foreach ( $themes as $theme ) {
		$name = $theme->get('Name');
		if ( isset( $wp_themes[ $name ] ) )
			$wp_themes[ $name . '/' . $theme->get_stylesheet() ] = $theme;
		else
			$wp_themes[ $name ] = $theme;
	}

	return $wp_themes;
}