(finish_struct): No pedwarn for field with enum type if size matches int.

(finish_struct): No pedwarn for field with enum type if size matches int.

(grokdeclarator): No error for void type for extern or global var.

(grokdeclarator): Warn here for volatile fn returning non-void type.
(start_function): Not here.

(grokdeclarator): Don't pass on const and volatile
fron function value type to function type.

From-SVN: r5084