Update ICU to 58.1

source/data/translit/Thai_ThaiLogical.txt

Index: source/data/translit/Thai_ThaiLogical.txt
diff --git a/source/data/translit/Thai_ThaiLogical.txt b/source/data/translit/Thai_ThaiLogical.txt
index 76ac08f59db12d7c64dcab69ef272bf4fb5dc32b..e7045cdeb7d705e284c8f905de10266790c40609 100644
--- a/source/data/translit/Thai_ThaiLogical.txt
+++ b/source/data/translit/Thai_ThaiLogical.txt
@@ -1,16 +1,22 @@
-# ***************************************************************************
-# *
-# *  Copyright (C) 2004-2015, International Business Machines
-# *  Corporation; Unicode, Inc.; and others.  All Rights Reserved.
-# *
-# ***************************************************************************
+# © 2016 and later: Unicode, Inc. and others.
+# License & terms of use: http://www.unicode.org/copyright.html#License
+#
 # File: Thai_ThaiLogical.txt
-# Generated from CLDR 
+# Generated from CLDR
 #
+
+# This reverses the Thai LogicalOrderException vowels, and does (part of) spaces
+# The rules that convert space into semicolon are in another file;
+# since they have to come BEFORE the break iterator
 $thai = [[:thai:] ก-\u0E3Aเ-๛] ;
+# First convert the semicolon back
 ' '  ← $thai { '; '  } $thai;
+# Remove any other spaces between thai letters
 ← $thai { ' ' } $thai;
+# Now vowels
 $thai_reversing = [[:Logical_Order_Exception:] & $thai];
 $thai_non_reversing = [$thai - $thai_reversing ];
 ( $thai_reversing ) ( $thai_non_reversing ) → $2 $1;
+# other direction
 $2 $1 ← ( $thai_non_reversing ) ( $thai_reversing ) ;
+