parse.y (sizeof, [...]): New non-terminals to increment skip_evaluation.

parse.y (sizeof, [...]): New non-terminals to increment skip_evaluation.

* parse.y (sizeof, alignof, typeof): New non-terminals to
increment skip_evaluation.  Replace terminals with them and
decrement skip_evaluation at the end of rules using them.
* decl2.c (mark_used): Don't assemble_external if
skipping evaluation.

From-SVN: r56726