EastAsianWidth.txt Format Change after Unicode 15.1.0 (#585)

* fix bin/generate_east_asian_width for Unicode 15.1.0

* fix a regexp of parsing EastAsianWidth.txt line

* Fix to use MatchData#[] instead of Regexp::last_match

bin/generate_east_asian_width

@@ -8,16 +8,11 @@ end
 open(ARGV.first, 'rt') do |f|
   list = []
   f.each_line do |line|
-    next if line.start_with?(?#)
-    line.chomp!.sub!(/ .*/, '')
-    next if line.empty?
-    range, type = line.chomp.split(';')
-    type = type.to_sym
-    if range =~ /\h+\.\.\h+/
-      first, last = range.split('..').map{ |_| _.to_i(16) }
-    else
-      first = last = range.to_i(16)
-    end
+    next unless m = line.match(/^(\h+)(?:\.\.(\h+))?\s*;\s*(\w+)\s+#.+/)
+
+    first = m[1].to_i(16)
+    last = m[2]&.to_i(16) || first
+    type = m[3].to_sym
     if !list.empty? and (list.last[:range].last + 1) == first and list.last[:type] == type
       list.last[:range] = (list.last[:range].first..last)
     else