Merge from emacs trunk: Use font-lock-ensure to avoid workaround.

 commit d6a1f0c99732ffed9959dfbfee3c4365b48e9398
  Author:     Stefan Monnier <monnier@iro.umontreal.ca>
  AuthorDate: Wed May 28 23:45:29 2014 -0400
  Commit:     Stefan Monnier <monnier@iro.umontreal.ca>
  CommitDate: Wed May 28 23:45:29 2014 -0400

    ...
    * lisp/progmodes/verilog-mode.el (verilog-preprocess): Disable workaround in
      recent Emacsen.