Merge "(bug 43801) add a getter for ICU version to ICUCollation"

diff --cc includes/Collation.php
index 7c2c05e,63cfbe1..7879ebe
--- 1/includes/Collation.php
--- 2/includes/Collation.php
+++ b/includes/Collation.php
@@@ -392,4 -374,21 +392,20 @@@ class IcuCollation extends Collation 
                }
                return false;
        }
+ 
+       /**
+        * Return the version of ICU library used by PHP's intl extension,
+        * or false when the extension is not installed of the version
+        * can't be determined.
+        *
+        * The constant INTL_ICU_VERSION this function refers to isn't really
+        * documented. It is available since PHP 5.3.7 (see PHP bug 54561).
+        * This function will return false on older PHPs.
+        *
+        * @since 1.21
+        * @return string|false
+        */
+       static function getICUVersion() {
+               return defined( 'INTL_ICU_VERSION' ) ? INTL_ICU_VERSION : false;
+       }
  }
 -