Ruby

parse.y: should not deent concatenated string

• parse.y (xstring): reset heredoc indent after dedenting,
  so that following string literal would not be dedented.
  [ruby-core:72857] [Bug #11990]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53555 b2dd03c8-39d4-4d8f-98ff-823fe69b080e