Code Modernisation: Introduce the spread operator in `wp-includes/formatting.php`.

Rather than relying `func_get_args()` to retrieve arbitrary function arguments, we can now use the spread operator to assign them directly to a variable.

Props jrf.
See #47678.
Built from https://develop.svn.wordpress.org/trunk@46128


git-svn-id: http://core.svn.wordpress.org/trunk@45940 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/formatting.php

@@ -4836,8 +4836,7 @@ function wp_pre_kses_less_than_callback( $matches ) {
  * @param mixed  ...$args Arguments to be formatted into the $pattern string.
  * @return string The formatted string.
  */
-function wp_sprintf( $pattern ) {
-	$args      = func_get_args();
+function wp_sprintf( $pattern, ...$args ) {
 	$len       = strlen( $pattern );
 	$start     = 0;
 	$result    = '';
@@ -4867,11 +4866,12 @@ function wp_sprintf( $pattern ) {
 		if ( $pattern[ $start ] == '%' ) {
 			// Find numbered arguments or take the next one in order
 			if ( preg_match( '/^%(\d+)\$/', $fragment, $matches ) ) {
-				$arg      = isset( $args[ $matches[1] ] ) ? $args[ $matches[1] ] : '';
+				$index    = $matches[1] - 1; // 0-based array vs 1-based sprintf arguments.
+				$arg      = isset( $args[ $index ] ) ? $args[ $index ] : '';
 				$fragment = str_replace( "%{$matches[1]}$", '%', $fragment );
 			} else {
-				++$arg_index;
 				$arg = isset( $args[ $arg_index ] ) ? $args[ $arg_index ] : '';
+				++$arg_index;
 			}
 
 			/**

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-46127';
+$wp_version = '5.3-alpha-46128';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.