an option to enable C9X features

[Jim Wilson <wilson at cygnus dot com>]

We need one.  Preferably, we want something that the gcc2 group will also
accept, so that we can avoid command line incompatibilities between gcc2 and
egcs.  I'm volunteering to take up this issue with the gcc2 group, but first,
I thought I would ask for comments here.

I believe that there have been two previous suggestions.  Ulrich Drepper
suggested these options
	-iso-c (defaults to c89)
	-iso-c=89
	-iso-c=9X
Paul Eggert suggested a more complete set of options
	-std=c9x		C9x
	-std=gnu		GNU C (the default)
	-std=iso9899:1990	ANSI C X3.159-1989 / ISO/IEC C 9899:1990
	-std=iso9899:199409	ANSI C as modified by Normative Addendum 1
	-std=iso9899:199?	equivalent to -std=c9x, whenever it comes out
	-std=lia1		LIA-1
	-std=traditional	K&R C

	-ansi			equivalent to -std=iso9899:1990
	-traditional		equivalent to -std=traditional

Both of them seem reasonable, but I'm inclined to propose the -std=X options
first, because they give us more flexibility, and would allow us to also
handle for instance C++ and Fortran standards the same way.  I don't like
the colons though.  If we can't get the gcc2 folks to accept that, though,
then I think that the -iso-c=X options are a reasonable compromise that
would allow us to start adding C9X features.

Jim