Fix performance of ruby syntax for new regexp engine

ruby_syntax.patch

diff --git a/syntax/ruby.vim b/syntax/ruby.vim
index e4bc98f..dac2d1a 100644
--- a/syntax/ruby.vim
+++ b/syntax/ruby.vim
@@ -117,10 +117,7 @@ syn match rubyPredefinedVariable "$_\>"  										   display
 syn match rubyPredefinedVariable "$-[0FIKadilpvw]\>"									   display
 syn match rubyPredefinedVariable "$\%(deferr\|defout\|stderr\|stdin\|stdout\)\>"					   display
 syn match rubyPredefinedVariable "$\%(DEBUG\|FILENAME\|KCODE\|LOADED_FEATURES\|LOAD_PATH\|PROGRAM_NAME\|SAFE\|VERBOSE\)\>" display
-syn match rubyPredefinedConstant "\%(\%(\.\@<!\.\)\@<!\|::\)\_s*\zs\%(MatchingData\|ARGF\|ARGV\|ENV\)\>\%(\s*(\)\@!"
-syn match rubyPredefinedConstant "\%(\%(\.\@<!\.\)\@<!\|::\)\_s*\zs\%(DATA\|FALSE\|NIL\)\>\%(\s*(\)\@!"
-syn match rubyPredefinedConstant "\%(\%(\.\@<!\.\)\@<!\|::\)\_s*\zs\%(STDERR\|STDIN\|STDOUT\|TOPLEVEL_BINDING\|TRUE\)\>\%(\s*(\)\@!"
-syn match rubyPredefinedConstant "\%(\%(\.\@<!\.\)\@<!\|::\)\_s*\zs\%(RUBY_\%(VERSION\|RELEASE_DATE\|PLATFORM\|PATCHLEVEL\|REVISION\|DESCRIPTION\|COPYRIGHT\|ENGINE\)\)\>\%(\s*(\)\@!"
+syn match rubyPredefinedConstant "\%([^.]\.\_s*\)\@<!\%(MatchingData\|ARG\(F\|V\)\|ENV\|DATA\|FALSE\|NIL\|STD\(ERR\|IN\|OUT\)\|TOPLEVEL_BINDING\|TRUE\|RUBY_\%(VERSION\|RELEASE_DATE\|PLATFORM\|PATCHLEVEL\|REVISION\|DESCRIPTION\|COPYRIGHT\|ENGINE\)\)\>\%(\s*(\)\@!"
 
 " Normal Regular Expression
 syn region rubyRegexp matchgroup=rubyRegexpDelimiter start="\%(\%(^\|\<\%(and\|or\|while\|until\|unless\|if\|elsif\|when\|not\|then\|else\)\|[;\~=!|&(,[<>?:*+-]\)\s*\)\@<=/" end="/[iomxneus]*" skip="\\\\\|\\/" contains=@rubyRegexpSpecial fold