parse.y: check single regexp only
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48673 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
parse.y: check single regexp only
content is a single regexp without interpolation.
[ruby-dev:48714] [Bug #10437]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48673 b2dd03c8-39d4-4d8f-98ff-823fe69b080e