MDL-72359 core: Changed MAX_TIME from 9999999999 to PHP_INT_MAX

This prevents automatic casting from int to double on 32 bit systems
(which have a maximum for integers of 2147483647)

Whilst Moodle will not support 32-bit systems for much longer, this is
still worth doing to prevent future issues.

analytics/classes/analysable.php

@@ -38,7 +38,7 @@ interface analysable {
     /**
      * Max timestamp.
      */
-    const MAX_TIME = 9999999999;
+    const MAX_TIME = PHP_INT_MAX;
 
     /**
      * The analysable unique identifier in the site.