Use simpler and faster code.

substr_compare() is up to 2x slower than just substr(). Use a faster,
more common, and simpler to read variant of the same thing.

lib/Cake/Network/CakeRequest.php

@@ -261,7 +261,10 @@ protected function _url() {
 		}
 		$endsWithIndex = '/webroot/index.php';
 		$endsWithLength = strlen($endsWithIndex);
-		if (strlen($uri) >= $endsWithLength && substr_compare($uri, $endsWithIndex, -$endsWithLength, $endsWithLength) === 0) {
+		if (
+			strlen($uri) >= $endsWithLength &&
+			substr($uri, -$endsWithLength) == $endsWithIndex
+		) {
 			$uri = '/';
 		}
 		return $uri;