LanguageNameSearch: do not mix different scripts in same buckets

To keep the average and maximum bucket size low, I made codepoints
< 4000 more granular and code points >= 4000 less granular. This
could be tweaked further for sure to reach more even sized buckets.

Bucket stats before:
 - 773 buckets
 - smallest has 1 entries
 - largest has 1804 entries
 - median size is 66 entries
 - average size is 45.394566623545 entries

Bucket stats after:
 - 698 buckets
 - smallest has 1 entries
 - largest has 1792 entries
 - median size is 16 entries
 - average size is 50.272206303725 entries

Change-Id: Id62d93658117564b05294c2fe36ca7c182784859

data/LanguageNameSearch.php

@@ -46,7 +46,15 @@ class LanguageNameSearch {
 	}
 
 	public static function getIndex( $name ) {
-		return self::getCodepoint( $name ) % 1000;
+		$codepoint = self::getCodepoint( $name );
+
+		if ( $codepoint < 4000 ) {
+			// For latin etc. we need smaller buckets for speed
+			return $codepoint;
+		} else {
+			// Try to group names of same script together
+			return $codepoint - ( $codepoint % 1000 );
+		}
 	}
 
 	/**