also -fugly-comma combined with `IARGC()' invocation:
* bad.def (FFEBAD_NULL_ARGUMENT_W): New diagnostic.
* expr.c (ffeexpr_finished_): Don't reject null expressions
in the argument-expression context -- let outer context
handle that.
(ffeexpr_token_arguments_): Warn about null expressions
here if -fpedantic (as appropriate).
Obey -fugly-comma for only external-procedure invocations.
From-SVN: r17793