Sort extensions alphabetically

This makes it easier to compare mime data from different sources.

Author: nikic

sapi/cli/generate_mime_type_map.php

@@ -36,10 +36,14 @@
     if (!isset($extensions[$ext])) {
         $extensions[$ext] = $mime;
     } else {
-        printf(STDERR, "Ignored exist mime type: $ext => $mime\n");
+        fprintf(STDERR, "Ignored exist mime type: $ext => $mime\n");
     }
 }
 
+uksort($extensions, function($ext1, $ext2) {
+    return strcmp($ext1, $ext2);
+});
+
 echo <<<HEADER
 /*
    +----------------------------------------------------------------------+