CC Mode: stop distinguishing brace blocks from defun blocks by content.

CC Mode: stop distinguishing brace blocks from defun blocks by content.

Don't merge to master; this is a quick fix for the emacs-26 branch.  This is
essentially a reversion of the patch from 2017-11-10 which attempted to handle
C99's compound literals.

The bug here was triggered when a defun block contained a declaration ending
in a comma, yet without a semicolon.

* lisp/progmodes/cc-engine.el (c-guess-basic-syntax): At the CASE 9 test,
remove from the `or' form the test of a block's contents.